EPA 823-R-07-006



## R EPORT OF THE 

## E XPERTS 

## S CIENTIFIC 

## W ORKSHOP 

## O N 

## C RITICAL


## R ESEARCH 

## N EEDS 

## F OR 

## T HE 

## D EVELOPMENT 

## O F 

## N EW 

## O R 

## R EVISED


## R ECREATIONAL 

## W ATER 

## Q UALITY 

## C RITERIA

Airlie Center Warrenton, Virginia

March 26-30, 2007

U.S. Environmental Protection Agency

Office of Water Office of Research and Development

June 15, 2007[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 i 

## D ISCLAIMER

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 participan ts and approval for publi cation does not signify

that the contents reflect the vi ews of the Agency and no official endorsement should be inferred.[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 iii 

## A CKNOWLEDGMENTS

EPA would like to thank th e experts and others w ho 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 proceedi ngs are greatly appreciated.

Workshop Chair: Denise Keehner, USEPA

Workshop Experts: Nicholas Ashbolt, USEPA Thomas Atherholt, New Jersey Depa rtment of Environmental Protection Michael Beach, Centers for Disease Control and Prevention Bart Bibler, Florida De partment of Health Alexandria Boehm, Stanfo rd 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 Fujioka, University of Hawaii, Manoa Toni Glymph, Wisconsin Depart ment 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 Wa ter and Atmospheric Research, New Zealand Charles McGee, Orange County Sanitation District, California Samuel Myoda, Delaware Depart ment 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 Clim ate Change Bureau, Health Canada Stephen Schaub, USEPAU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 iv Mark Sobsey, University of North Carolina, Chapel Hill Jeffrey Soller, Soller Environmental, California Michael Tate, Kansas Department of Health and Environment Peter Teunis, RIVM (National Institute of Pub lic Health and the Environment), Netherlands Gary Toranzos, University of Puerto Rico, Rio Piedras Timothy Wade, USEPA John Wathen, USEPA Stephen Weisberg, Southern Californi a 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 La kes 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 atte nded the workshop and their affiliations and contact information, including wo rkshop experts, EPA resource personnel, and meeting support personnel (note takers, m eeting facilitator, logistics staff).

Report cover photo credits: Charles Hagedorn, Virginia Tech, Blacksburg Lawrence Honeybourne, Orange County Health Care Agency, Santa Ana, CaliforniaU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 v 

## T ABLE OF 

## C ONTENTS

D ISCLAIMER

............................................................................................................................... .................................... I

A CKNOWLEDGMENTS

............................................................................................................................... .................. III

T ABLES AND F IGURES

............................................................................................................................... .................. IX

A CRONYMS

............................................................................................................................... ................................... XI

I NTRODUCTION

............................................................................................................................... ..............................1

1. A PPROACHES TO C RITERIA D EVELOPMENT ...........................................................................................................9

1.1 B ENCHMARKS FOR C RITERIA D EVELOPMENT ...................................................................................................11

1.2 I NTEGRATION OF W ORKSHOP C OMPONENTS .....................................................................................................12

1.3 S UMMARY OF C URRENTLY A VAILABLE W ATER Q UALITY C RITERIA S ETTING A PPROACHES ...........................13 1.3.1 WHO Approach for Wa ter Quality Cr iteria Se tting......................................................................... .....13 1.3.2 EU Approach for Wa ter Quality Cr iteria Se tting .......................................................................... ........15

1.3.3 EPA 1986 Water Quality Crite ria Setting ................................................................................. ............16 1.3.4 Summary of Proposed Cr iteria Developmen t Appro aches....................................................................1 8 1.3.5 Other Approaches Considered ............................................................................................. .................20

1.4 S UMMARY OF C RITICAL I SSUES TO BE R ESOLVED IN A PPLYING A VAILABLE W ATER Q UALITY C RITERIA
A PPROACHES

............................................................................................................................... ....................20 1.4.1 Summary of Appli cation of WHO Approach fo r U.S. Criteri a Setting.................................................21 1.4.2 Summary of Appli cation of EU Approach fo r U.S. Criteri a Setting.....................................................23 1.4.3 Summary of Applica tion of EPA 1986 Approach fo r U.S. Criteri a Setting..........................................23

1.5 S UMMARY OF R ESPONSE TO W ORKGROUP C HARGE Q UESTIONS ......................................................................24

1.6 C ONCLUDING R EMARKS

............................................................................................................................... ....33

2. P ATHOGENS , P ATHOGEN I NDICATORS , AND I NDICATORS OF F ECAL C ONTAMINATION .....................................35

2.1 A PPLICATION OF M ICROBIAL /B IOMARKER P ARAMETERS .................................................................................37

2.2 T IERED T OOLBOX M ONITORING A PPROACH .....................................................................................................38

2.3 P ARAMETERS FOR H AZARDOUS E VENT P OLLUTION M ONITORING ....................................................................39

2.3.1 Microbiolo gical Parameters .............................................................................................. ....................39

2.4 T RADITIONAL FECAL INDICATORS ( COLIFORMS & ENTEROCOCCI ) ....................................................................40

2.5 A LTERNATIVE F ECAL I NDICATORS ...................................................................................................................41

2.5.1 Bacteria ................................................................................................................ .................................41 2.5.2 Bacteriophages .......................................................................................................... ............................43 2.5.3 EU Project Summary of Tracers ........................................................................................... ................46

2.6 P ATHOGENS AND P ATHOGEN I NDICATORS ........................................................................................................47

2.7 C HEMICAL B IOMARKERS OF F ECAL C ONTAMINATION ......................................................................................49

2.7.1 Fecal Sterols........................................................................................................... ...............................49

2.7.2 Caffeine................................................................................................................ .................................49 2.7.3 Optical Brighteners and Other Sewage Markers ............................................................................ .......50

2.8 R ESEARCH N EEDS

............................................................................................................................... ..............51

2.8.1 Within a 1 to 3 Year Timeframe .......................................................................................... .................51 2.8.2 Longer-term Research Goals.............................................................................................. ...................52

3. M ETHODS D EVELOPMENT

............................................................................................................................... ......57

3.1 I NTRODUCTION

............................................................................................................................... ..................59

3.2 C LASSES OF I NDICATORS

............................................................................................................................... ...60

3.3 E VALUATING N EW M ETHODS FOR E XISTING I NDICATORS ................................................................................62

3.3.1 Health Risk Evaluation .................................................................................................. .......................62 3.3.2 Establishing Equivalency be tween New and Stan dard Methods...........................................................63

3.4 P ERFORMANCE C RITERIA

............................................................................................................................... ...63

3.5 E VALUATION P ROCESS FOR A LTERNATIVE (N EW ) I NDICATORS ........................................................................66U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 vi 3.6 E VALUATING S OURCE I DENTIFICATION M ETHODS

- P ROFICIENCY AND E VALUATION ......................................67 3.6.1 Library-independent Methods ............................................................................................. ..................67

3.6.2 Non-microbial Methods ................................................................................................... .....................68 3.6.3 Library- Based Me thods................................................................................................... ......................68

3.7 M ODIFICATIONS TO THE E VALUATION P ROCESS W HEN I NDICATORS ARE U SED FOR O THER A PPLICATIONS ....68

3.8 R ESEARCH N EEDS

............................................................................................................................... ..............69

4. C OMPARING R ISK ( TO H UMANS ) FROM D IFFERENT S OURCES ............................................................................75

4.1 I NTRODUCTION

............................................................................................................................... ..................77

4.2 S UMMARY OF W ORKGROUP D ISCUSSIONS AND R EFLECTIONS ON W ORKGROUP -S PECIFIC C HARGE AND Q UESTIONS

............................................................................................................................... .......................80

4.3 O PTIONS FOR A PPROACHES AND I MPLEMENTATION C ONSIDERATIONS .............................................................82

4.4 R ESEARCH N EEDS

............................................................................................................................... ..............83 4.4.1 Epidemiological Studies................................................................................................. .......................83 4.4.2 Quantitative Microb ial Risk As sessment .................................................................................. ............85

4.4.3 Etiolo gic Agents........................................................................................................ ............................86 4.4.4 Fate and Transport...................................................................................................... ...........................87 4.4.5 Determine the Occurrence of Pathog ens in Affected R ecreational Waters...........................................88

4.4.6 Bather Studies .......................................................................................................... .............................89

4.4.7 Additi onal Res earch..................................................................................................... .........................89

5. A CCEPTABLE R ISK

............................................................................................................................... ..................91

5.1 I NTRODUCTION

............................................................................................................................... ..................93

5.2 M AIN C ONCLUSIONS AND O BSERVATIONS ........................................................................................................93 5.2.1 Whether the Term ‘Acceptable Risk ’ is Still the Most Appropriate Term............................................93

5.2.2 Public Involvement in ‘Acceptable Risk ’ Decisi ons....................................................................... ......94 5.2.3 ‘Acceptable Risk’ Levels for the Genera l Popula tion..................................................................... ......95 5.2.4 ‘Acceptable Risk’ Levels for Vulnerable Subgroups....................................................................... .....97

5.2.5 What are the Current Levels of Protection from Ex isting Crite ria? ......................................................9 9 5.2.6 Potential Synergies for Health Protection between Revised Recreational Water Criteria and Standards for Drinking Water Sources and Shellfish Harv esting Waters ..........................................100

5.2.7 Areas of Discord ........................................................................................................ .........................100

5.3 R ESEARCH N EEDS

............................................................................................................................... ............100

6. M ODELING A PPLICATIONS FOR C RITERIA D EVELOPMENT AND I MPLEMENTATION ........................................105

6.1 I NTRODUCTION

............................................................................................................................... ................107 6.1.1 Water Qua lity Notifi cation.............................................................................................. ....................107 6.1.2 Sanitary Inve stigation Models............................................................................................ ..................109

6.2 H OW M ODELS ARE C URRENTLY B EING U SED .................................................................................................110 6.2.1 Sanitary Inve stigation Models............................................................................................ ..................110 6.2.2 Water Quality Notification Models....................................................................................... ..............111

6.2.1 Communication of Modeled Information to the Public and Recreati onal Water Managers ...............113

6.3 A DVANTAGES AND D ISADVANTAGES OF M ODELING ......................................................................................114 6.3.1 Advantages of Modeling .................................................................................................. ...................114 6.3.2 Disadvantages of Modeling............................................................................................... ..................115

6.4 M ODEL D EVELOPMENT AND E VALUATION .....................................................................................................117 6.4.1 Initiating Model Development for Water Quality Notification...........................................................11 7 6.4.2 Model Development for Water Quality Notifica tion ........................................................................ ..117 6.4.3 Data Needs for Simple Sanitary Investigation Model Development...................................................119

6.4.4 Cost Estimates.......................................................................................................... ...........................119 6.4.5 Understanding the Unce rtainty and Measuring Success of Statistical Models....................................119

6.5 R ESEARCH N EEDS

............................................................................................................................... ............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. I MPLEMENTATION R EALITIES .............................................................................................................................12 9U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 vii 7.1 A PPLICATION TO S PECIFIC P ROGRAM A REAS ..................................................................................................131 7.1.1 Beach Monitoring and Water Quality Notif ication Prog rams.............................................................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 Workgr oup Members as to Vi ews/Observations..............................140

7.2 E VALUATION OF A LTERNATIVE A PPROACHES FOR C RITERIA D EVELOPMENT ................................................140 7.2.1 WHO Approach ............................................................................................................ ......................141 7.2.2 EU Approach............................................................................................................. ..........................143 7.2.3 Existing U.S. Mo del – 1986 Criteria..................................................................................... ..............144 7.2.4 Alternative Approaches.................................................................................................. .....................145

7.3 R ESEARCH N EEDS

............................................................................................................................... ............145 7.3.1 Near-term (Next 1 to 3 Years)........................................................................................... ..................146 7.3.2 Long-term (Beyond 3 Years) .............................................................................................. ................147

A PPENDIX A: C HARGE TO THE E XPERT W ORKGROUP M EMBERS

........................................................................ A -1

A PPENDIX B: P ARTICIPANT L IST

............................................................................................................................. B -1

A PPENDIX C: T RANSLATION OF E PIDEMIOLOGY TO D ISEASE B URDEN BY WHO AND EU................................... C -1

A PPENDIX D: S UMMARY OF THE E UROPEAN C OMMISSION D IRECTIVE

................................................................ D -1

A PPENDIX E: I NDICATOR T ERMINOLOGY

............................................................................................................... E -1

A PPENDIX F: S UMMARY OF M EASUREMENTS C URRENTLY P LANNED FOR THE D OHENY AND M ALIBU
B EACH (C ALIFORNIA ) E PIDEMIOLOGY S TUDY

.................................................................................. F -1

A PPENDIX G: D EVELOPMENT OF D ETERMINISTIC M ODELS

.................................................................................. G -1[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 ix 

## T ABLES AND 

## F IGURES

T ABLE 1. WHO C LASSIFICATION M ATRIX FOR I NTEGRATING M ICROBIAL W ATER Q UALITY AS
M EASURED BY E NTEROCOCCI D ENSITY WITH S ANITARY I NSPECTION C ATEGORY ............................14

T ABLE 2. N UMERICAL M ICROBIOLOGICAL W ATER Q UALITY A SSESSMENT C LASSIFICATION FOR F RESH (I NLAND ) AND M ARINE (C OASTAL AND T RANSITIONAL ) B ATHING W ATERS FOR THE 24 EU

M EMBER S TATES

............................................................................................................................... 16

T ABLE 3. S UMMARY OF EPA’ S 1986 R ECOMMENDED W ATER Q UALITY C RITERIA FOR B ACTERIA AND
2004 R ULE

............................................................................................................................... ..........17

T ABLE 4 A . S UMMARY OF P ROPOSED C RITERIA D EVELOPMENT A PPROACHES : S TRENGTHS AND
L IMITATIONS

............................................................................................................................... ......18

T ABLE 4 B . S UMMARY OF T HREE P ROPOSED C RITERIA D EVELOPMENT A PPROACHES : B ENCHMARKS ...............19

T ABLE 5. C OMPARING R ISKS ( TO H UMANS ) FROM D IFFERENT P ATHOGEN S OURCES .......................................78

T ABLE 6. R ESEARCH N EEDS AND R ANKINGS FROM F IVE “A CCEPTABLE R ISK ” W ORKGROUP M EMBERS .......103

T ABLE E-1. D EFINITIONS FOR I NDICATOR AND I NDEX M ICROORGANISMS OF P UBLIC H EALTH C ONCERN ........E-1

T ABLE F-1. S UMMARY OF M EASUREMENTS C URRENTLY P LANNED FOR THE D OHENY AND M ALIBU
B EACH (C ALIFORNIA ) E PIDEMIOLOGY S TUDY ................................................................................. F-1

T EXT B OX E-1. D EFINITIONS OF K EY F ECAL I NDICATOR M ICROORGANISMS ...........................................................E-1

F IGURE 1. F LOW D IAGRAM OF H OW THE W ORKGROUP C OMPONENTS C ONTRIBUTE TO THE
D EVELOPMENT OF N EW OR R EVISED R ECREATIONAL W ATER Q UALITY C RITERIA .............................3

F IGURE 2. C LEAN W ATER A CT : W ATER Q UALITY S TANDARDS O VERVIEW ........................................................5

F IGURE 3. F LOW D IAGRAM OF H OW THE W ORKGROUP T OPICS C ONTRIBUTE TO THE D EVELOPMENT AND
I MPLEMENTATION OF N EW OR R EVISED R ECREATIONAL W ATER Q UALITY C RITERIA ......................13

F IGURE 4 A . E NTEROCOCCI (MPN/100 M L) S AMPLED E VERY 10 M INUTES AT A B EACH IN C ALIFORNIA ...........108

F IGURE 4 B . S UBTROPICAL M ARINE B EACH (M IAMI

, F LORIDA ): 48 HOURS S AMPLING ......................................108

F IGURE 5. T HE P OSSIBLE F ATES OF M ICROBES (F ECAL I NDICATORS AND P ATHOGENS ) IN
E NVIRONMENTAL W ATER AND S EDIMENT ......................................................................................124

F IGURE C-1. A P ROBABILITY D ENSITY F UNCTION OF F ECAL I NDICATOR D ISTRIBUTIONS M EASURED AT A
R ECREATIONAL W ATER S HOWING P ROBABILITY OF E XPOSURE (Y A XIS ) VERSUS L OG 10

F ECAL S TREPTOCOCCI C ONCENTRATION .........................................................................................C-2

F IGURE C-2. T HE D OSE

- RESPONSE R ELATIONSHIP D ERIVED F ROM K AY ET AL

. (1994) ( A ) AND THE
F UNCTIONAL F ORM U SED TO D ERIVE THE 2003 WHO G UIDELINE V ALUES ( B )..............................C-2

F IGURE C-3. C OMBINING THE D OSE

- RESPONSE C URVE AND THE PDF TO P RODUCE A R ELATIVE D ISEASE
B URDEN A SSESSMENT FOR ANY B EACH OR R EGION ........................................................................C-3[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 xi 

## A CRONYMS

7Q10 the lowest streamflow for 7 consec utive days that occurs on average once every 10 years AWQC ambient water quality criteria ASABE American Society of Agri cultural and Biological Engineers ATP adenosine triphosphate

BEACH Act Beaches Environmental Assessment and Coastal Health Act of 2000 BMP Best Management Practices CAFO concentrated animal feeding operation

CDC Centers for Disease Control and Prevention cfu colony forming unit

CSO combined sewer overflow

CWA Clean Water Act DNA deoxyribonucleic acid DU designated use EHEC enterohemorrhagic E. coli EPA U.S. Environmental Protection Agency EU European Union FDA U.S. Food and Drug Administration FFU focus forming units GC/MS gas chromatography-mass spectrometry GI gastrointestinal GIS geographic information systems GM geometric mean HACCP Hazard Analysis Cr itical Control Point HEV hepatitis E virus

HIV/AIDS human immunodefici ency virus/acquired immu ne deficiency syndrome HPLC high performance liquid chromatography HSPF Hydrological Simulation Program-Fortran

ILSI International Life Sciences Institute IMS immunomagnetic separation ISO International Organiza tion for Standardization

L Liter

mL Milliliter

MPN Most Probable Number MST microbial source tracking NASBA nucleic acid sequence based amplification NEEAR National Epidemiological and Environmental Assessment of Recreational Water Study

NOAA National Oceanic and A tmospheric Administration NPDES National Pollutant Discharge Elimination System NPS non-point source program

NWS National Weather Service PCR polymerase chain reaction pfu plaque forming unitU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 xii POP probability of precipitation POTW publicly owned [wastewater] treatment works QMRA quantitative microbial risk assessment qPCR quantitative polymerase chain reaction

RCT randomized controlled trial

RDS relative standard deviation RMSE root mean square error

RNA ribonucleic acid SAFE Swimming Advisory Forecast Estimate

SCCWRP Southern California Co astal Water Research Project

SD standard deviation SETAC Society of Environmental Toxicology and Chemistry SRC sulphite-reducing clostridia SSM single sample maximum SSO sanitary sewer overflow STEC shiga-toxin producing E. coli SWMM Storm Water Management Model TMA transcription-mediated amplification TMDL total maximum daily load UAA Use Attainability Analysis U.K. United Kingdom URI upper respiratory illness

U.S. United States USGS U.S. Geological Survey UV ultraviolet light WQS Water Quality Standards WHO World Health Organi zation (United Nations)U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 1 

## I NTRODUCTION

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 signifi cant advances, particularly in the areas of molecular biology, mi crobiology, and analytic al chemistry. EPA believes that that

these new scientific and technical advances need to be factored into th e development of new or revised Clean Water Act (CWA) Section 304(a) cr iteria for recreation. To this end, EPA has been conducting research and assessing relevant sc ientific 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 cr iteria, specifically for

Great Lakes and coastal marine waters.

From March 26 through 30, 2007, EPA convened a group of 43 nationa l and international technical, scientific, and implem entation 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 defe nsible new or revised CWA §304( a) recreational ambient water quality criteria (AWQC) in the near-term. Nea r-term needs were defined as specific research and science activities that could be accomplished in 2 to 3 years so that re sults are available to EPA in time to support the development of new or revised criteria. The ne w or revised criteria, which would be available from EPA in roughl y 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 de velop this new or revise d criteria in a highly participatory framework within the next 5 ye ars 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 si milar in organization and format to the Society of Environmenta l Toxicology and Chem istry (SETAC) Pellston Workshops, where technical experts in a particul ar subject area are inv ited to participate and evaluate current and prospective environmental issues. A Pellston-type workshop typically brings together between 40 to 50 technical ex perts from academia, business, government, and public interest groups. Experts are semi-sequest ered for up to a week to facilitate focused

discussions and individual and collaborative writing of a dr aft summary report by the end of the workshop. Subject leaders are then responsib le for consolidating, editing, producing, and distributing the final (for mal) workshop proceedings.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 2 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 partic ipant 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 professiona l facilitator. The proper ba lance 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 ex ternal experts to voi ce 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 fr om the workshop discussions and these proceedings. Monday af ternoon the seven workgroups met for the first time to discuss interpretation of the charge que stions (Appendix A). On Tuesday, all workshop participants met in a plenary session, which was followed by workgroup sessions th roughout the day. The agenda facilitated and encouraged the workgroups to meet with each other to discuss common and overlapping issues. At the e nd of the day the workshop participants met again in plenary to hear report-outs from each workgroup chair th at described their pr ogress 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 bot h stay informed of and build on each other’s discussions. In addition to several joint breakou t 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 be gan writing a draft workgroup report. The workgroups continued writing on Thursday. Frid ay morning, each workgroup turned in a 10 to 20 page draft report and their resp ective chairs provided an overvi ew of each repor t regarding the major themes discussed and critical res earch needs in a final plenary session.

Seven Workgroup Topics

The seven workgroup topics are pres ented in seven chapters in th is report. The relationships between these and other topics ar e graphically represented in Fi gure 1. In Figure 1 shaded boxes correspond to the seven workgroups. The alternativ es boxes in Figure 1 refer to various possible indicators that a toolbox approach could provide for each of the CWA app lications. The charge questions helped the workgroups to define the scope of their discussions. Th e experts were asked to provide their individual insights on the state of the scie nce 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 3 Figure 1. Flow Diagram of How the Workgroup Components Contribute to the Development of New or Revised Recreational Water Quality Criteria.

1. Approaches to Criteria Development – focus on a toolbox approach as well suggest other potential approaches for new or revised criteria development.

2. Pathogens, Pathogen Indicators, and I ndicators of Fecal Contamination – discuss the strengths and limitations of indicators of fecal contamination, pathogen index microorganisms, and specific pathogens for de velopment of new or revised recreational AWQC.

3. Methods Development – discuss methods for quantifyi ng indicators and pathogens, such as culture-based methods, molecular-based me thods (e.g., quantitati ve polymerase chain reaction [qPCR]), and faster culture-based methods and their app licability for AWQC.

4. 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.

5. Acceptable Risk – discuss the level of risk to various populations that would be associated with numeric AWQC. EPA was inte rested 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.

6. Modeling Applications to Criteria Development and Implementation – discuss predictive modeling approaches and their potential applications in implementation of AWQC. Criteria Development Chapter 1 Indicator(s) Chapter 2

“Acceptable

Risk” Chapter 5

Implementation

Realities Chapter 7 Method(s) Development

Chapter 3

Risks to Humans

from Different

Sources Chapter 4

Assessment

(based on monitoring data) NPDES Permitting Primary
Contact

Waters Alternatives for Water Quality

Notification

TMDLs Predictive Modeling Chapter 6 Other

Indicators Alternatives

AlternativesU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 4 7. Implementation Realities – identify and consider factor s 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) e xpressed as numeric concentrat ions 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 eff ective standards used in CWA regulatory and non-regulatory programs. Figure 2 pr ovides 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 c ontact 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, surfi ng, 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 concentr ation that should not be exceeded; a daily value or seasonal concentrat ion that should not be exceeded; or a value that should not be exceeded, on average, mo re than one time every 3 years (for acute aquatic life criteria).

• AWQC are often associated w ith EPA-approved analytical methods. This is partly because without EPA-approved methods to measur e 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 Stat e 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 5 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 publis h new or revised water quality criteria for pathogens and pathogen indicators (including a revised list of testing met hods, as appropriate) for the purpose of protecting public health in coas tal recreation waters. Co astal recreation waters 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 nume ric criteria cannot be determined
Also:

• EPA reviews changes to State or Tribal cr iteria for protection of the designated use and scientific defensibility

• State and Tribal criteria are not effect ive for CWA purposes until approved by EPA

• In the case of multiple DUs, criter ia must support the most sensitive use

• State-adopted and EPA-approved State and Tribal WQS form the regulatory compliance numbers for CWA purposes

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 g uidance onl yU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 6 are marine and Great Lake waters designated by St ates for use for swimming, bathing, surfing, or

similar water contact activities. Under CWA §303(i)(1)(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 sta ndards if they are scientifically defensible and protective of the designated use.

Once approved, State WQS become effective fo r CWA purposes. This means that the Stateadopted §304(a) criteria become regulatory sta ndards and are used for several different CWA purposes, including the following:

• §303(d) listings. Under §303(d) of the CWA, States pr epare 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 ar e in place for a pollutant, must have discharge limits as stringent as necessa ry 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 r eceive BEACH Act grants for their beach monitoring and public notification programs. Those States use their recreational contact WQS to determine whether to close an ar ea 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 situationallyappropriate indicators/methods a nd increased options for implemen tation, 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 appr oach for recreational water quality criteria might be the following:

The toolbox approach is a set of potential mi crobiological (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 th e 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 rega rdless of which tool is used.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 7 Although the toolbox concept allows a context for considering feasibility and applicability of

different indicator and method co mbinations in developing new or revised recreational criteria under CWA §304(a), it is critical that there is an understandi ng of the relationship among the different methodologies for proper implementati on 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 th e meaning of those multiple measures (i.e., linkage) in the context of th e overall CWA §304(a) program. Without a clear understanding of the linkage and context of different met hods the entire “toolbox” concept becomes unmanageable from a regulatory perspective.[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 9 

## C HAPTER 

## 1

A PPROACHES TO 

## C RITERIA 

## D EVELOPMENT

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 Cha nge Bureau, Health Canada Jeffrey Soller , Soller Environmental, California David Whiting , Florida Department of Environmental Protection[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 11 1.1 Benchmarks for Criteria Development

The workgroup was charged with answering 21 ques tions and providing a range of alternatives for the development of new or revised nationa l 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) Worl d 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 In dex. The workgroup members concentrated the discussions on the three approaches that were d eemed most appropriate for consideration in the context of Clean Water Act (C WA) Section 304(a) ambient wate r quality criteria (AWQC), namely, the WHO approach (with possible modifi cations), the EU approach (adopted 2006), and

a modified version of EPA’s 1986 criteria. Be fore the workgroup defined the approaches and determined the potential appli cation of the three alternativ e approaches, workgroup members agreed that it was critical to id entify desirable attributes or be nchmarks for the criteria. The

benchmarks or attributes that we re 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 h ealth effects demonstrated in epidemiology

studies.

2. The criteria should demonstrat e utility for and be compa tible with all of the CWA §304(a) criteria (as amended by the Beaches Environmental Assessment and Coastal Health Act of 2000 [BEACH Ac t]) 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 Discha rge Elimination System (NPDES) permits.

3. The criteria should be scientif ically defensible for applic ation in a wide variety of geographical locations (clima tic conditions), including fres h 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 recr eational water impacted by sewage effluent, concentrated animal feed operation (CAFO) contaminated runoff, non-point sources (e.g., agriculture [non-CAFO], urba n runoff) and waters not impacted by anthropogenic

sources.

5. The criteria should be sufficiently robust and fl exible so that they can be configured to provide regulators the ability to protect susceptible (sen sitive) subpopulations such as children and immunocompromised indivi duals. Commonality was found among workgroup members that protecting the health of children was of paramount concern.

6. The criteria are associated (lin ked) 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 trop ical waters equally. Similarl y, the criteria should provide equal protection those exposed to effluent, urban runoff, and/or non-point source runoff impacted waters via pr imary contact recreation.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 12 The workgroup members agreed that all seven of th e 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 develo ped. 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 shoul d 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 pub lic notification needs.

1.2 Integration of Workshop Components

A summary of the interactions between the variou s 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 Figu re 3 refer to various possible indica tors that a toolbox approach could provide for each of the CWA app lications. 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 availa ble and usable for the implementation of the proposed parameter. Different methods have di fferent 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 hu man health from different sources of fecal contamination (Chapter 4). On ce identified, the pathogen/pathogen indicator and the associated method are used during the criteria development process. Another criti cal component in the criteria development process is the identifica tion 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 devel opment process. The Modeling workgroup discussed how predictive modeling can be used to inform cr iteria approaches and to provide information on water quality notification (Chapter 6). Once thes e pieces were integrated, an initial check was conducted against the suggestions and concerns of the Implemen tation Realities workgroup (see Chapter 7) members to help ensure that the po tential for criteria development does not conflict with actual “on the ground” implementation.

As discussed in the Introduction to these proceedings, recreationa l 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 dependi ng on the framework, a number of

alternate indicators or methods ma y be used to assist in maki ng the determination as to the overall quality of a waterbody and the complian ce with the underlying cr iteria. Second, these criteria are used to determine permit limits for NPDES permit holders and for TMDL purposes. Finally, these criteria are used to determine th e acceptability of the wa ter for direct primary contact recreation. Conceptually, alternative indicators, including m odels, could also be used for these purposes.

2 http://www.epa.gov/owow/tmdl/tmdl0103/U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 13 Criteria Development Indicator(s)

“Acceptable

Risk”

Implementation

Realities Method(s) Development

Risks to Humans

from Different

Sources

Assessment

(based on monitoring data) NPDES Permitting Primary
Contact

Waters Alternatives for Water Quality

Notification

TMDLs Predictive Modeling Other

Indicators Alternatives

Alternatives

Figure 3. Flow Diagram of How the Workgroup Topics Contribute to the Development an d Implementation of New or Revised Recreational Water Quality Criteria.

1.3 Summary of Currently Available Water Quality Criteria Setting Approaches

The three alternatives that we re identified by the workgroup we re 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 ep idemiology studies and some version of each of

these frameworks are in use curr ently in at least one country.

Workgroup members generally agreed that all three criteria devel opment approaches are feasible providing the criteria meet th e becnhmarl/attributes listed above. Although the workgroup briefly discussed other approaches such as th e EPA’s Air Quality Index, HAACP, and Heal the Bay’s Beach Report Card approaches, none of thes e 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 i ssues associated with recreational water environments for many years and has published seve ral influential reports that represent a well accepted view among international experts (Prüss, 1998). The WHO approach provides a basisU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 14 for standard setting in light of local and re gional circumstances, such as the nature and

seriousness of local endemic illne ss, exposure patterns, and compe ting health risks that are not associated with recreational water exposure.

The WHO approach is based on the perspective th at recreational water qu ality and protection of public health are best described by a combinati on of sanitary inspection and microbial water quality assessments (the WHO [2003] Guidelines use enterococci as th e fecal indicator of choice; see Table 1). This approach consider s 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 assessmen t category” in Table 1), and combines them into a five-level

classification scheme for recreational water enviro nments. To date, the classification system has been used primarily to “grade” recreational wate rs 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 ri sk of acquiring gastrointestinal (GI) illness for (A) <1 case in 100 exposures, (B) <1 case in 20 e xposures, (C) <1 case in 10 exposures, and (D) >1 case in 10 exposures. The 95 th percentile value was selected as an appropriate descriptor of the microbial probability density function because it is easily unde rstood 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.

SOURCE: WHO, 2003.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 15 polluted water and focuses on water quality that is likely to cause illness (i.e., grea ter probability of illness associated with increasing density of human sources of fecal pollution). The WHO

levels of risk for the bands described above we re selected based on a series of science policy

decisions in consultations with numerous in ternational 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 w ould be similar or more protective than the risk levels adopted by other devel oped 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 categ ory derived for an area. WHO experts believe that the three most important sources of human fecal contamin ation of recreational wa ter environments for public health purposes are typically sewage, riveri ne 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, depe ndent 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 ar e relatively high, further explor ation of the source(s) and their relative risks would be recommended. This highe r level of examination (tier) may utilize more expensive methods and approaches and further cy cles (tiers) of inves tigation as necessary. Based on the results of the sanitary inspections, recreational waters are ra nked (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 Qu ality Criteria Setting

The EU broadly adopted the 2003 WHO Guidelin es in formulating the 2006 Bathing Water Directive. A summary of the European Commis sion Directive is provided in Appendix D. The approach incorporates the fo llowing fundamental elements:

• The EU starts with the WHO risk assessm ent framework, but does not include the sanitary inspection category information for the purposes of recreational water classification. Instead, it uses only the micr obial water quality assessment information to characterize the probability of exposure to human pathogens.

• The EU approach used the WHO microbiologica l criteria for marine waters and applied the same risk assessment framework to new ep idemiological data to derive standards for

fresh recreational waters.

• The EU approach allows sample discounti ng. Under discounting, numeric excursions above the water quality standards that are pr edicted 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 95 th 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 sy stem are in place to inform the public about short-term pollution events derived duri ng predictable conditions (e.g., rainfall).

The EU Bathing Water Directive (7/EU/EEC; da ted February 15, 2006) is currently being translated by Member States for implementa tion (EP/CEU, 2006). The Directive establishesU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 16 separate numerical microbiological criteria fo r 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 Ka y et al. (1994) and Wiedenmann et al. (2006)— the former was used by WHO in formulating th eir Guidelines (Kay et al., 2004; WHO, 2003).

Table 2. Numerical Microbiological Water Qu ality Assessment Classification for Fresh (Inland) and Marine (Coastal and Tr ansitional) Bathing Waters for the 24 EU

Member States.

Inland (Fresh) Waters

Indicator Excellent Good Sufficient (Intestinal) enterococci (cfu/100 mL) 200 * 400 * 360 **

E. coli (cfu/100 mL) 500 * 1,000 * 900 **

Coastal and Transitional (Marine) Waters

Indicator Excellent Good Sufficient (Intestinal) enterococci (cfu/100 mL) 100 * 200 * 200 **

E. coli (cfu/100 mL) 250 * 500 * 500 **

Notes: * = Based on a 95 th percentile evaluation; ** = Based on a 90 th percentile evaluation to

reduce the risk of statistical anomalies when usi ng a small data set, which also allows lower limit

values for enterococci and E. coli 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 conducte d 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. Gast roenteritis describes a va riety of diseases that affect the GI tract and are rarely life-threatening; self-limiting symptoms include nausea, vomiting, stomachache, diarrhea, headache, and fe ver. 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 qua lity 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 defi ne their designated use of “p rimary contact recreation” to encompass recreational activities that could be expected to result in the ingestion of, or immersion in, water, such as swimming, water sk iing, surfing, or any othe r recreational activity where ingestion of, or immers ion 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 e xposed 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 17 Table 3. Summary of EPA’s 1986 Recommended Water Quality Criteri a for Bacteria and

2004 Rule

Geometric Mean Single Sample Maximum Allowable Density Indicator SwimmingAssociated

Gastroenteritis Rate per 1,000

Swimmers Steady State

Geometric Mean

Indicator Density Designated

Beach Area Moderate: Full Body

Contact

Recreation Lightly Used: Full Body

Contact

Recreation Infrequently

Used: Full Body Contact

Recreation

Freshwater

Enterococci 8 33 61 78 107 151

E. coli 8 126 235 298 409 575

Marine Water

Enterococci 19 35 104 158 276 501

Source: US EPA (2004).

EPA’s 1986 bacteria AWQC document provides ge ometric mean densities as well as four different single sample maximum values (repre senting 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 cons ervative) 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% conf idence level. The lowest confidence level corresponds to the highest level of protection.

In the 1986 AWQC context, single sample maximu m 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 va riability 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 concentra tion of enterococci in a single sample would be over 158/100 mL. The higher the single sample maxi mum, the lower the probability that a single sample exceeding that value would occur as part of the norma l 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 relationshi ps identified in the epidemiol ogy studies leading up to the 1986 criteria are not appropri ate or representative of all U.S. wa ters. For example, States have concern that the most appropriate indicator in tr opical waters may be different than in temperate waters, and that appropriate levels of indicator s 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 re garding use of the single sample maximum values and differing risk levels;

• no EPA-approved analytical methods for use in wastewater for the indicator bacteria;U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 18 • lack of data to correctly a ssess 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 l ack of flexibility to adjust th e 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 Cr iteria Development Approaches: Strengths and Limitations

Criteria Approach Science Supporting Approach Strengths Limitations

World Health Organization (WHO, 2003) Fleisher et al.,

1996 Kay et al., 1994,

2004 WHO, 1999 Wyer et al., 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 Kay et al., 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 (75 th
percentile) has been criticized from implementation perspective

• Credibility concerns in many parts of the U.S.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 19 Table 4b. Summary of Three Proposed Criteria Development Approaches:

Benchmarks

Criteria Approach Criteria Attribute Approach Compatible with

Attribute

Health-based Yes

CWA §304(a) applications Most challenging – unclear how different grades for beaches would be interpreted with respect to impaired waters; for example, TMDLs would need to be

considered.

Geographic variability Not with current indicator, ongoing research could fill gaps

Point vs. non-point No, epidemiological data would be

needed

Multiple subpopulations Could be, but in current configuration children not analyzed separately
Uniform risk across waterbody types Yes World Health Organization (WHO, 2003)

Linked to method that is validated Yes currently, but will also depend on

future indicators

Health-based Yes, but differential risks from different

sources of fecal contamination is not included, thus, this approach is less health-based than WHO approach

CWA §304(a) applications Yes, but challenging for same reasons as WHO approach

Geographic variability Not with current indicator, ongoing research could fill gaps Point vs. non-point No

Multiple subpopulations Could be, but in current configuration children not analyzed separately
Uniform risk across waterbody types Yes European Union (EP/CEU, 2006)

Linked to method that is validated Yes currently, but will also depend on

future indicators

Health-based Yes, but concern about single sample standard, also concerns that differential

risks from different sources of fecal

contamination are not included CWA §304(a) applications Yes Geographic variability No Point vs. non-point No
Multiple subpopulations No

Uniform risk across waterbody types No, fresh and marine recreational waters have different “acceptable risks”; this

could be addressed in new or revised

criteria Current U.S.

Criteria (US EPA, 1986)

Linked to method that is validated Yes currently, but will also depend on

future indicatorsU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 20 1.3.5 Other Approaches Considered

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

• Hazard Analysis and Critical Contro l Point Principles (HACCP);

• Heal the Bay Beach Report Card; and

• EPA Air Quality Index.

The EU, EPA (1986) criteria, and the WHO appro aches 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 propos ed water regula tion 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 workgrou p 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 Reso lved in Applying Available Water Quality Criteria Approaches

No matter which recreational water quality criteri a development approach is selected, a number

of research needs have to be met before crit eria 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 c onditions listed above also is critical. The epidemiological studies should al so include (1) culture-based me thods in addition to molecular methods for enterococci; (2) culture and molecu lar-based methods for E. coli in fresh water

studies because national freshwater criter ia 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 th e 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 organi sms in wastewater treatment plants and in the ambient aquatic environment. Workgroup memb ers expressed a significant concern about the issue of conservation of measurable genetic mate rial throughout the treatment process because of the regulatory ramifications in the NPDES, wa ter quality assessment, and TMDL programs of moving to molecular-based criteria.

Another research need is for effective predictiv e 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 me thods 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 laborat ory, 18 to 24 hour incubation tim e, and time required for resultsU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 21 to reach and be evaluated by a decision maker). In addition to their development, the models need to be adequately field veri fied and calibrated. Ideally, regi onal 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 ve rify, and calibrate the models s hould not be cost prohibitive to collect. At a minimum, recreati onal beach managers should consid er a simple, predictive rainfall model to more effectively protect public health.

Workgroup members emphasized that a sanitary investigation 3 approach to characterize drainages to primary contact recr eational 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 para meters for criteria development. To clarify expectations for these surveys, a standardized a nd relatively simple approach would need to be developed that includes fecal bacteria source characterization (public ly owned [wastewater] treatment works [POTWs], storm drain outfalls, CAFOs, on-site wastewater treatment systems [“septic systems”], agriculture, etc.) on a draina ge-wide basis, distance of sources to primary contact recreational waters, flow, developed ar ea 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 tracking 4 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 follo wing research is conduct ed 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 expr essed concern that use of that specifi c 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. Howe ver, “sanitary inspection” is used wh en the WHO approach is described.

4 Although there is no t universal acceptance of defin itions for microbial source trac king and microbial source identification, the Methods workgroup discussions assume d 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 watershe d that material came from, but it does suggest what to look for upstream. Sour ce tracking is determination of the actua l source of fecal matter, such as a leaking pipe, a septic system, or a cow pasture. It typica lly involves using some of the marker techniques associated with source identification, but not necessarily. Source tr acking can also be achieved through extensive spatial sampling with existing indicators or (for example) through use of dye tablets in septic systems.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 22 1. Analyze epidemiological data to determine the values of water quality that corre spond to the identified levels of “accepta ble risk” for the indicator of fecal contamination using the selected method(s).

2. Identify a suitable indicator of fecal cont amination or suite of fecal indicators (particularly for subsequent tiers of investigation). Th is 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). Se e Chapter 5 for a discussion of the process through which an “accep table risk” level could be chosen.

4. Derive a quantitative sanitary investigation category rather than a qualitative process; also, the sanitary investigation s hould be standardized nationwide.

5. Statistically validate the linkages between different in dicator/method combinations for different CWA §304(a) purposes to facilit ate translation between the various

indicator/methods.

6. Consider and develop a recreati onal water quality reclassifica tion scheme, if appropriate. If such a reclassification scheme is appr opriate, 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 repres ent 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 a nd associated implementation guidance concurrently.

To apply the WHO (2003) approach for future crit eria setting, the followi ng issues will need to be considered in detail and expanded:

1. Develop a process to determine how wa terbodies get listed as impaired.

2. Determine the appropriate number of categorie s for microbial and sa nitary investigation categories.

3. Possibly change several qualitative determin ations 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 NPDE S dischargers (consideration for default to most restrictive category).

5. Determine how to use different indicat or/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 subs tantially different

than from human sources.

7. Determine what is the most appropriate metric for expressing the water quality criteria (geometric mean, upper percentile, a co mbination of those and/or other)U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 23 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 vett ed quantitative sanitary inve stigation guidance; here the workgroup members suggested a tiered approach that allows for varying levels of effort based on likely benefit from the assessment (h igh and low risk should be easier to assess [i.e., beaches downstream from POTWs or ur ban catchments would be high risk, and

beaches downstream of catchments with 100 % natural sources would be low risk]). Although completion of the sanita ry investigation does not n eed to be required, surface

waters would default to the most restrict ive criteria until such time as a completed investigation provides jus tification for changing the applicable criteria.

10. Develop a well described and vetted recrea tional 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 classifi cation scheme based on a quantitative sanitary investigation would not be necessary because th e sanitary inspection category is not used to determine the beach classification, and (2) it woul d not be necessary to determine whether health

risks from nonhuman sources of fecal contaminati on are substantially diffe rent than from human sources, because the beach classification is based on microbial densities only..

To apply the EU approach for futu re criteria setting the same issu es 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 previ ously would be applicable to new or revised U.S. criteria development with the following modifications:

1. Develop additional indicators and analytical me thods 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 24 2. Consider more timely methods for beach monitoring and water quality notification. Currently, there is no scientific evidence s upporting beach water quality determinations based on, at best, day-old (culture-based) data.

a. If molecular-based methods are used, th en 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 me thods 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 shoul d 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 95 th percentile, a 5% exceedance sh ould 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.) e xposed 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 fo r setting limits of pollutant s that may be relevant for developing nationally recommended recreatio nal 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/ECU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 25 • 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) a pproaches are already being used for the intende d purpose, either in the United Stat es 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 recrea tional water quality criteria.

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

Workgroup members identified the following criti cal benchmarks for wa ter 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., tropi cal, subtropical, and temperate regions);

• Address potential differences between point and non-point sources of fecal contamination and associated risk;

• Consider risks to susceptible subpop ulations, primarily children; and

• Be based upon methods that are reliable and reproducible.

Based on these benchmarks, workgroup members furt her identified three approaches for further consideration—European Union Revised Bathi ng 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 scien ce sufficient and of adequate quality?

Epidemiological research identified to s upport the best selected approaches was:

• European Union Revised Bathing Wate r Directive (2006/7/ EC; EP/CEU, 2006)

o Fleisher et al. (1996)U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 26 o Kay et al. (1994)

o Weidenmann et al. (2006)

o Wyer et al. (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 Fleisher et al. (1996)

o Kay et al. (1994)

All members of the workgroup agreed that th e research reports lis ted above support the respective approaches but some members questione d whether the research identified above was adequate to meet all of the identified benc hmarks. 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 wa ter quality criteria development in the United States.

4. Are there any critical research and scie nce needs that should be addressed in developing or selecting an appropriate appro ach? 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 subtropi cal fresh and marine recreati onal 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 hum an and nonhuman sources of fecal contamination;

• Information on sources of runoff (e.g., c oncentrated animal feeding operations [CAFOs]) from both marine a nd fresh recreational waters;

• How much water are bathers ingesting while swimming?; and

• Fate and transport of indicators (and pa thogens) in the aquatic environment.

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

• Comparison of prospective cohort and ra ndomized control trial epidemiological studies;

• Identification of pathogens (viruses, bacteria , or parasites) responsible for GI illnesses at bathing beaches;U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 27 • 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 clarif y the objectives of environmental health assessments (sanitary in vestigations) and microbi al source tracking

methods.

5. Is a “toolbox” approach appropriate for developing new or revi sed recreational criteria in the near-term? Why or why not?

The Approaches to Criteria Development wor kgroup members interpreted the concept of a toolbox approach differently. Some members be lieved that shifting from the current (US EPA, 1986) criteria approach to eith er the WHO (2003) or EU (EP/CE U, 2006) model approach would constitute a type of toolbox approa ch. For example, the sanitary i nvestigation as us ed within the WHO approach could be considered to be an additional tool in the implementation of the new or

revised criteria. Others believe d the toolbox approach meant the us e 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 inte gral part of the toolbox. Models that have been both validated

and calibrated are critical for a ccurately predicting recreational waters that exceed criteria. Improved notification via forecasting models is lik ely 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 workgr oup 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 exam ple, the use of different fecal indicators that demonstrate improved indicator/illness rate relations hips in subtropical or tropical waters would

reduce the likelihood of these wate rs inappropriately being listed as impaired under the CWA.

The use of some form of san itary investigations, as within the WHO (2003) approach, would potentially allow for discounting those waters th at were identified as having limited or no anthropogenic fecal loading, thereby avoiding those waters being listed as impaired inappropriately.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 28 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 differe nt CWA §304(a) needs. There was also concern about the feasibility of establishing requisite and defensib le linkages between the va rious indicator/method combinations that could comprise the toolbox.

7. What are the desired features or characteristics that wo uld make a “toolbox” approach appropriate?

Any additional fecal indicator or pathogen measure within the toolbox would need to have proven indicator/illness rate rela tionships, or at a mini mum, have a linkage to another indicator

that does. The characteristic of being interrelated (correlate d) 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 ju st one aspect of the CWA §304(a) needs. Any

of the tools within the toolbox should be va lidated, either by predictive modeling or by

correlation to other tools within the toolbox. Add itionally, if a management action is initiated on the results of a particular tool within th e toolbox (e.g., a beach closure based on qPCR) the follow up action should also be based upon the sa me tool (beach opened based on qPCR), to the extent possible.

8. Would a “toolbox” approach achieve additional pu blic health protec tion 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 th e listing of tropical or subtropi cal waters as im paired due to the poor indicator/illness relationship for these wate rs) 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 th e same approach could be us ed for waters designated as secondary contact as used for primary contact, m eaning that epidemiologically-based health data could be used to define acceptable exposure lim its. QMRA could also be used for these purposes to supplement available epidemiological information.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 29 10. What are critical research and science need s in developing or selecting an appropriate approach for secondary contact recreation?

Additional epidemiological stud ies may be needed under seconda ry contact conditions. These epidemiological studies should ad dress the same data needs as those proposed in support of the primary recreation criteria. Alte rnatively, QMRA could be used if exposure data are available.

Can this research be complete d in time to be used in criteria development in the nearterm?

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 notifi cation, (2) development of NPDES permits, (3) assessments to determine use attain ment, and (4) development of TMDLs?

All three approaches—the (EPA) 1986 criter ia, EU (EP/CEU, 2006), and WHO (2003) approaches—would require additional epidemiologi cal studies to implement. Given additional epidemiological data with a dditional indicators, it is possi ble that each approach could potentially be implemented and could support mu ltiple 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 implementa tion (e.g., field sampling issues, laboratory challenges, staff training, etc.)?

If future epidemiological studie s do not identify additi onal indicator tools th at 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 discoun ting 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 deve lopment of new or revised recreational water quality criteria.

Geographic Applicability

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

No. Different regions of the country have different potentia ls for regrowth, persistence, indicator/pathogen die off rates (UV exposure), and indicator/illn ess rate relationships. The literature supports the conclusion that additiona l indicators will be n ecessary to accurately identify those recreational waters that are at ri sk across all geographic regions of the country.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 30 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 th e 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 combinati on, the indicator/illness relations hip. Alternatively, the toolbox might include environmental health and safety a ssessments (sanitary investigations) that allow for the discounting of waters that appear as impaired based upon the indi cator 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 n eeds in developing or selecting an approach that will appropriately factor-in diverse geographical conditions?

Additional epidemiological studies are needed that provide improved i ndicator/illness rate relationships for all regions of the United Stat es. These additional epidemiological studies

should focus on recreational waters that are under a va riety of potential pa thogen sources (e.g., sewage, urban runoff, non-point sources, non-anthropogenic sour ces). Where possible, the various potential sources of pa thogens should be considered w ithin a single epidemiological study rather than each being considered in separa te studies. This might be possible by examining waters that have varying source s depending upon rainfall or clim atic conditions. For example,

California beaches that have urban runoff sour ces during wet weather but no known point or non-point sources during dry weather.

To pursue the 2003 WHO approach, a quantitative e nvironmental 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 c ontamination. 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 program s and the overarching goal of protecting and restoring waters for swimming, what prot ection is provided by establishing a 30- day “average” value as the criteria?

There was some commonality of workgroup member opinion on th is issue. Several members

felt that the criteria would best be expressed as a geometric mean and/or a standard deviation orU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 31 95 th percentile. Several members believed that thes e 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 prov ided by a daily or instantaneous maximum

value?

The added value provided by an instanta neous maximum value is dependent upon the

indicator/illness rate associati on. Short-term variability associ ated with the current indicators limit the usefulness of single sample maximu m values; however, using qPCR or other non culture-based methods may improve the util ity of single sample values. Additional epidemiological data is needed to assist in ma king 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 measur e 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 scien tific 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 ag reement 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 va lues are not effective for beach monitoring purposes. This may change somewhat if the sh ift from culture-based methods to non culturebased methods improves the issues with variabi lity and indicator/illness rate relationships.

There is potential to use single values, whet her culture- or non-cultur e based, in predictive models for beach monitoring. The geom etric mean, standard deviation, or 95 th percentiles show promise for multiple CWA programs. So long as th ere 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 li ttle data to support the us e of instantaneous or daily values derived from culture-based methods from Day 1 to predict the n eed to post or close recr eational waters on Day 2. There are recent epidemiological data (Wade et al., 2006) that indi cates that qPCR (non culture)-based indicator methods may be effectiv e for same day notification at some beaches.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 32 Group members identified several critical research need s 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 co ncentration over 30 day s and not recommend a single sample maximum, do we understand th e illnesses that coul d 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 pa rticular water body c ould be significantly different than the criteria from which it was derived;

• the variability of indicator could chan ge 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 othe r 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) asse ssments to determine use attainment, and (4) development of TMDLs? Are there practica l considerations that could preclude, or greatly limit, the usage in routine, regu latory implementation (e.g., field sampling issues, laboratory challeng es, staff training, etc.)?

To address this questio n it was separated into the followi ng 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 criter ia may not be applicable to tropical and subtropical beaches could present an unaccepta ble 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, si ngle sample maximum values are not necessarily required and in fact may not be necessary. Thes e types of criteria coul d be useful for beachU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 33 monitoring and water quality notification. Re garding TMDLs, single sample maximum values do not seem applicable for TMDLs for indicator bacteria.

1.6 Concluding Remarks

The workgroup members did not speci fically prefer one criteria a pproach over another primarily

because it is believed that additional data th at will become available from epidemiological studies within the next 2 to 3 years and how t hose data will inform the criteria development process is not yet known. For example, it is no t 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 WH O-based criteria approach.

Further, it was the opinion of workgroup members th at there may be differences in the ability to implement each of the three approaches if all of th e 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 satisfact ory if most or all of the criter ia 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 us e 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 nearterm research.

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Wiedenmann, A; Kruger, P; Di etz, K; Lopez-Pila, JM; Szew zyk, 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 experime ntal health-related cl assification for marine

waters. Water Research 33(3): 715-722.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 35 

## C HAPTER 

## 2

P ATHOGENS 

## , P ATHOGEN 

## I NDICATORS 

## , AND



## I NDICATORS OF 

## F ECAL 

## C ONTAMINATION

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[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 37 2.1 Application of Microb ial/Biomarker Parameters

The charge of the Pathogen, Pathogen Indicato rs, 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, in cluding total maximum daily load (TMDL) implementation, and National Pollu tant Discharge Elimination System (NPDES) implementation using microbial and chemical indi cators. The discussions were limited to constituents for which methods are currently available or expected to be available with in the next 3 years and focused around the following four issues:

1. Fecal matter indicators (as surrogates for ga strointestinal [GI] and non-GI illnesses);

2. Pathogens and their index organi sms (GI and non-GI illnesses);

3. Application of fecal indicator s, 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 qualit y 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 an d 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 re creational waters impacted primarily by point sources of human sewage.

Since development of the currently used 1986 AWQC, research has s hown that this narrow health effects-based standard (i.e., epidemiologi cal studies at beaches with point sources of human sewage) is limited in th at it does not take into account differences in geographical conditions, ecology of microorganisms, and varying s ources of fecal indicator bacteria. In this regard, the expected relationship between illness a nd 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 resu lt of replication of the i ndicator bacteria in the environment, such as in soil, sediments, storm dr ains, or on plants or aquatic vegetative matter. Initially, replication of fecal indicator bacter ia 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 i ndicators across different geographic and climatic regions.

It is for the above reasons that experts in the fi eld of microbial water qual ity generally agree that the principles of microbial ecology must be considered in water quality assessment. Understanding and applying these principles requi res an assessment of the sources of fecal contamination, selection of the appropriate met hods used to assess these sources, a connection between the intended AWQC application, and the f ecal and/or pathogen i ndicator or pathogen measured and an analysis of that indicator’s fa te and transport. Because of this understanding, workgroup members suggested a tiered assessment of a watershed, starting with traditional fecal indicators (conservative measures), and progr essing to select a suite of indicators ofU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 38 contamination (providing source specificity and contaminant load information). A characterization of contaminant inputs through a sa nitary investigation of the watershed and the waterbody being assessed should be undertaken, specifically assess ing 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 (t raditional) monitoring fecal indicators (i.e., E.

coli , enterococci) and the e xpected presence of human pathogens . This initial assessment should assist in understanding the re lationship 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 appr oach was preferred by workgroup members rather than promoting use of one pa rticular 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 cont aminant levels and sources that impact a given

recreational water site. Based on that informa tion, the indicator used in monitoring or the predictive modeling tool most appropriate for each CWA AWQC applica tion and contamination

source would be selected for the situation. Wa ter quality assessment for each recreational water site should begin with the simplest analyses a nd 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 environm ental sources of feca l contamination could subsequently be used if deemed necessary.

If a sanitary investigation determines that f ecal 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 in testines. If the source of the “fecal” indicator organisms is determined to be from the environm ent (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 th at does not amplify in the environment, such as spores of Clostridium perfringens or male-specific (F+) coliphages measured by culture- or molecularbased 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 monito ring, infectivity and/or molecu lar methods could be used for specific groups of pathogens such as, fo r bacterial pathogens (shiga-toxin producing E. coli [STEC] or Salmonella ), for protozoa ( Cryptosporidium or Giardia ), and for representative human sewage-borne viruses (ent eroviruses, adenoviruses, pol yomaviruses, 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 co mparison of new indicators, and/or pathogens and their respective methods would be advantage ous assuming a national repository database and sample archive facility could be established.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 39 Several non-GI illnesses have been associated with recreational us es of water but these are not addressed by monitoring for fecal indicator micr oorganisms or chemicals because the etiological agents for these waterborne dis eases come from non-sewage sources. Examples include animal urine ( Leptospira spp.), shedding fr om human skin ( Staphylococcus aureus ), or microorganisms that are naturally present in freshwater environments ( Aeromonas hydrophila

, Naegleri fowlerii

, Legionella pneumophila ). Further, several human pathogenic Vibrio species ( V. cholerae

, V. vulnificus

, V. parahaemolyticus

, V. alginolyticus ) are indigenous to marine and brackish waters.

Because reliable indicators have not been de veloped 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 investigat e a hazardous event (sewage disc harge, rainfall impact, etc.) would be to assay for fecal indicators (appropriate for a climatic/geographic area of concern, see Section 2.4). The primary indicato rs of fecal contamination are E. coli or enterococci; however,

based on the classification from an initial san itary investigation, alte rnatives 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 additiona l microbial indicators (see Section 2.5) are generally pr eferred over chemical biomarkers (see Section 2.7).

Focused sampling during and after higher risk peri ods 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 gr oup(s) should dictate the type of indicator to assay. For example, for rainfall in an area possi bly 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 i ndex tests include shiga-toxin producing E. coli or Cryptosporidium . This approach assumes that some background level of th e targeted group is known for the area of concern (s ee 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 a dopt the current (US EPA, 1986)

criteria for E. coli and enterococci. In N ovember 2004, EPA promulgate d a final rule that put federal standards in place for the 21 coastal st ates that had not adopted the 1986 criteria or

established criteria as protective of human health as EPA’s 1 986 criteria. However, these federal criteria apply only to coastal states and GreatLakes waters. In many cases, a fecal coliformbased 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 40 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. Fo r example, wastewater treatment/disinfection may be effective in reducing the number of these tr aditional fecal indicators but ineffective in reducing/inactivating some pathogens of concer n (Blatchley et al., 20 07). Some industrial treatment systems may contain/enable replication of high number of “fecal indicators,” which are not necessarily associated with fecal source s (Degnan, 2007; Gauthier and Archibald, 2001).

Ambient water and soils in tr opical 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 wate rs (Ashbolt et al., 1997; Barnes and Gordon, 2004; Davies et al., 1995) and thes e indicators have al so been found to pers ist in U.S. beach sand/sediments (Whitman et al., 2006).

The range of strains of fecal indicators identifi ed by traditional culture-based methods may differ from those identified by enzyme-based and quantitative polymerase chain reaction (qPCR [molecular])-based methods. Furt her, the strains more associat ed 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 discrimi nation of strains; however, less expensive typing kits do not accurately provide such discrimination fo r environmental strains. It is important to note then when quantifying fecal indicator organisms, different methods target different strains. For example, cells stressed by wastewater disi nfection 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 ar e used, both viable and non-viable cells are detected. In addition, the number of gene targ ets 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-1), 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 th an 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 microbi al 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 indi cators that have a clea r link to GI illness and upper respiratory disease in bath ers in marine and fresh recrea tional waters (Kay et al., 2004).U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 41 There are, however, several shortcomings in th e 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, pe rsonal communication, 2007), greater fecal specificity ma y result from spec ific identification and enumeration of E. faecalis or E. faecium or molecular-based methods targeti ng specific genes with in these species (e.g., ribosomal RNA or enterococcal cell su rface-associated pr otein and its gene Esp ) (Lehner et al., 2005; Liu et al., 2006). However, no robust me thod is currently available that readily provides such information, nor has this concept b een 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 anim al fecal matter, but un like 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 fe ral 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. coli and enterococci in soil/sand, sediment,

and water make those indicator organisms less useful (Byappanah alli and Fujioka, 1998; Hardina and Fujioka, 1991; Roll and Fujioka, 1997). Fo r example, in ambient streams in Hawaii, concentrations of fecal coliforms, E. coli , and enterococci consistently exceed recreational Water Quality Standards due to contribution by extr a enteric sources (Hardina and Fujioka, 1991, Luther and Fujioka, 2004). Thus, mon itoring 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 contaminati on event (Fujioka and Byappanahalli, 2001).

The presence of C. perfringens (spores) in water, therefore provides evidence of existing human/urban fecal contamination, which may re flect either recent or historical fecal

contamination from humans or animals. Alt hough methods have been available for some time,

confirmation of a robust and consistent method a pproach should be developed. For example, the advantages of heat-treating samp les (or not) to remove backgr ound vegetative cells and induce spore germination remains unclear.

The environmental resistance of C. perfringens spores has both advantag es 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 environmentU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 42 that they may not indicate the presence of pa thogens 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 differe nces in the extent of their

association with settleabl e particulate matter (Characklis et al., 2005; Krometis et al., 2007). To date, limited data have b een collected on any poten tial relationship between C. perfringens

counts and recreator health outcomes (see Section 2.8).

Bacteroides

Bacteroides spp. are members of the normal microbiot a of warm blooded animals and studies have shown them to be among the most preval ent genera in feces (Holdeman et al., 1976). Because they are strict anaerobes that grow in th e GI tract of humans and animals, they do not survive for long periods of time und er aerobic conditions (Kreader et al., 1998). However, their survival under different redox potential conditi ons (e.g., sediments) ha s not been thoroughly

studied. Recent research based on molecular met hods has demonstrated that some isolates may be strictly associated with hum an 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 speci ficity 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 diffe rentiate 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 robus t 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 cond itions (Betancourt and Fujioka, 2006; Seurinck et al., 2006). Either way, it is unclear whether qu antification of human/anim al fecal loads will be consistent or indeed possible using these molecular-based methods.

Though data from molecular techniqu es have shown that there is sp ecificity in th e 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 det ection methods. Methods that focus on one target may have reduced sensitivity as a resu lt 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 micr oorganisms. The fact that qPCR detects both live and dead organisms needs to be considered when data ar e applied in different c ontexts (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, US EPA, 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 envi ronmental conditions. Thus, the presence of

Bacteroides may have possible use as an indicator of health effects. Because the concentrationU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 43 of Bacteroides spp. in feces is much higher than othe r fecal bacteria, once the persistence of PCR-detected types is better unde rstood, it may also be useful for TMDL applications, although this possibility needs further evaluation.

The molecular methodology for the detec tion of general and human-specific Bacteroides spp. is already being tested and has proven to be r obust (Gawler et al., 2007; Walters et al., 2007). Thus, if detection methods are validated in the Un ited 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 (virus es) 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 taxono mically very diverse, covering the following six virus families: three families of doubl e-stranded DNA viruses ( Myoviridae

, Styloviriae

, Podoviridae ), two families of single-stranded DNA phages ( Microviridae and Inoviridae ), and one family of si ngle-stranded RNA viruses ( Leviviridae ).

Coliphages that infect via the host cell wall of E. coli are called somatic co liphages (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, an d 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 l ack of readily available and convenient methods to distinguish or specifically detect the diffe rent groups has made it difficult to determine which, if any, are effective fecal, trea tment 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 li ttle information on the sources and ecology of the somatic coliphages, especially fo r 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-f ecal environmental sources.

Male-specific coliphages have been studied extensively as fecal indicators and for

water/wastewater treatment/disinfection efficac y. Furthermore, F+ RNA coliphages can be distinguished genetically (via nucleic acid detection met hods) 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 an imal fecal waste (Furuse et al., 1975; Hsu et al.,U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 44 1995; Osawa et al., 1981) in the United States. Male-specific coliphages have been included in some epidemiological studies of recreational wate r. In the recent study by Colford et al. (2007)

at a marine recreational water site impacted primarily by non-poi nt source fecal contamination, F+ coliphages were the only micr obial indicator whose levels we re 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 t ypical bacterial indicators like E. coli and fecal coliforms (coliphages may behave similarly to human viruses during wastewat er 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 stan dardized 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 si mple immunological (particle agglutination) method scored by simple visual examination (Love and Sobsey, 2007). The method can be conducted in an MPN format to quantify concentra tions of the different F+ coliphage groups (F+ DNA and F+ RNA Groups I, II, III, and IV).

These findings indicate that robust, simple, rapi d, 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 valuab le if water samples from upcoming EPA and SCCWRP (Southern California Coastal Water Res earch 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 devel oped and validated. In addition, research is suggested to compare the perfor mance of methods for rapid coli phage detection by short-term enrichment-particle agglutination and qPCR and to consider the advantages and disadvantages of these two methods for app lication to recreational wa ter quality monitoring.

Limitations of Coliphages as Indictors

Although effective methods are avai lable to recover, detect, and quantify coliphages, limitations and unsolved problems with these methods remai n. The single agar layer method (EPA Method 1601) for enumeration of coliphages by counting pla ques 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 met hod makes it more difficu lt 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 difficultU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 45 to detect and isolate minority coliphages that gr ow more slowly and to lower concentrations. However, detection of all of the different colipha ges present as a mixture in enriched sample is possible by either nucleic aci d or immunological (particle immunoagglutination) methods.

The ecology of both somatic and F+ coliphages remains poorly documented and inadequately

understood. Information is lackin g on bacterial host range, source s, occurrence, and behavior (survival, transport, and fate) in different geographical regions havi ng different climates (temperate, subtropical, and tropi cal) and in waters and wastew aters of different microbial quality.

F+ coliphages can also be detected by molecu lar-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 qP CR methods to detect the broad range of F+ DNA and F+ RNA coliphages and their subgroups. Neve rtheless, research is now in progress to further improve F+ RNA qPCR by developing a nd performance-validating primer sets for all four genogroups of F+ RNA coliphages (Stepha nie Friedman, EPA Environmental Effects Research Laboratory Laboratory, personal comm unication, 2007). Reliable methods have not been developed for genetic analysis and char acterization of different somatic coliphage taxonomic groups.

Very few studies have been conducted to eval uate F+ coliphages as predictive indicators of

human health risks from recreati onal use of water. The most extensive study was conducted by Colford et al. (2007). That st udy 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 me thod) 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 recreatio nal waters according to EPA collaborative study protocols. Additional studies of this type are needed to clar ify 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 da ta initially supported the use of B. fragilis HSP40, which is specific to phages that only occur in human f eces. 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 contam ination 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 additi on, there is research th at indicates specificU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 46 Bacteroides hosts are susceptible to phages that are possibly useful for MST, which would be beneficial for its use for CWA §304(a) crite ria (Chung and Sobsey, 1993; Ebdon et al., 2007).

Limitations of Bacteroides Phages as Indicators

The diversity of phages including their specif icity for human host strains is not yet well characterized over a range of locations. This t ype 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 nationa l AWQC would be reduced. Many laboratory personnel may not have the experience required to work with an aerobic microorganisms; however, little additional laboratory equipment would be required. Because detection methods have not been standardized in the United States, it would likely take seve ral years to develop st andardized 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 a ll aquatic environments. In a European multilaboratory study, different microb ial and chemical indicators were analyzed in order to distinguish human fecal sources from nonhuman fecal sources us ing wastewaters and slurries from diverse geographical areas across Europe. Twenty-six parameters, which were later

combined to form derived variables for statis tical analyses, were ob tained by performing methods that were achievable in all the partic ipant laboratories and in clude the following:

enumeration of fecal coliform ba cteria, enterococci, clostridia, somatic coliphages, F+ RNA phages, bacteriophages infecting Bacteroides fragilis RYC2056 and Bacteroides

thetaiotaomicron GA17, and total and sorbitol-fermenti ng bifidobacteria; ge notyping 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-ethylcopro stanol, and epicoprost anol), although no one source identifier alone provided 100% correct classi fication of the fecal source. Subsequently, 38 variables (both single and derive d) were defined from the measured microbial and chemical parameters in order to find the best subset of variables to develop pred ictive models using the lowest possible number of measured parameters. To this end, several statistical or machine learning methods were evaluated and provided tw o successful predictive models based on just two variables that provided 100% correct classifica tion—(1) the ratio of th e 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 bacter ia. Other models with high rates of

correct classification were devel oped but they required higher num bers of variables (Blanch et al., 2006).U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 47 2.6 Pathogens and Pathogen Indicators

Many beach regulators and scientis ts believe that there are sign ificant opportunities to utilize specific pathogens or pathogen indices to better understand or characterize potential health risks from recreational exposures. Some reasons fo r not doing so, however, remain—especially that pathogen numbers are generally significantly lower and more va riable than fecal indicator organisms. Nonetheless, pathoge ns could be utilized to accurately determine risks as there have

been a number of studies that define actual hu man 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 wa ter quality monitoring to assess the risks from exposure. Also, it is possible th at an entire “class” of pathoge n risks can be determined by the presence of an “index pathogen” representing that group. The cu rrent capabilities of molecular methods to detect, identify, and enumerate pathoge ns has increased regula tors’ and stakeholders’ interest in seeing these applied to ambient water quality monitoring to be tter 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 di scharges, the data from which could then be used to conduct quantitative microbial risk assessment (QMRA) studi es 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 pat hogens (an example would be the use of a virus

model to assess the recreational risks from avia n influenza [H5N1] because this virus can be

released from infected human and animal feces [especially waterfowl] and can directly or indirectly contaminate re creational 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, identificati on, and enumeration, (1) the traditional culture-based techniques that are es pecially useful in determining viability of the sampled materials; and (2) the molecular-ba sed methods (PCR, antibody-based, and metabolicbased) that generally cannot di stinguish between viab le and non-viable pathogens, but which may be quite useful in further differentiating or speciating pat hogens in water samples. The

culture-based methods are useful for recreational wa ters in that they can determine if there is a viable disease risk from exposure while the mol ecular methods may not be capable of discerning viability.

Moreover, the culturable isolate can be further ch aracterized for the presence of human virulence genes and compared to clinical isolates in wate rborne disease outbreaks. In contrast, molecularbased methods may not be capable of discerni ng viability alt hough the presence of virulence genes can also be assayed by molecular methods. Because molecular methods do not recover the entire microorganism, further characteriza tion of that microorganism is limited.

Specific tracking of host sources us ing molecular techniques for pat hogens can be very useful in setting TMDLs, as it can help identify the source of the pathoge n and its magnitude. Recent improvements in molecular science applicat ions have brought about a capability toU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 48 simultaneously sample and evaluate large numbe rs of pathogens (e.g., microarray technology). Microarray technology still require s high concentrations of pathoge ns 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 enteri c and non-enteric disease contaminants, their levels, and potential risks associated w ith their presence in recreational waters.

Workgroup members expressed some concerns about using either specific pathogens or pathogen

class indices as a first tier m onitoring 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 c ontributes to analytical variability. Second, pathogen presence is typically spor adic in a community as many wa terborne 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 risk s. 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 stra in virulence or infectivity poten tial 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 no t 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 ex creting any specific pathogen or index pathogen. Thus, large wastewater treatment systems may always contribut e a small level of pathogens of concern while septic systems or small treatment systems may not have enough contributio n from the infected population to ensure that those effluents would c ontain specific pathogens of concern to use as a

routine measure of contamination—even if the di sease 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 i ndex organisms (or model organisms) in a toolbox or tiered approach to monitoring if consid ered as other than as a first tier measure of fecal contamination. In a toolbox approach, the determination of the pr esence and concentration of specific pathogens or their i ndex organisms could be useful to characterize risks once it has

been determined that there is a trigger level of fecal contaminat ion at a given recreational water site. Dose-response data for a number of the prim ary 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 re sults, and expertise n eeded 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) coul d allow States to determine sources and concentrations of the pathogens for particular upstream contamin ation events. Also, pathogens could be incorporated into fu ture NPDES permit limits and be used in the future to assessU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 49 wastewater treatment plant discharges for sp ecific 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 criter ia uses. Methods for MST in aquatic environments have been developed and discusse d above that distinguis h animal from human sources in the United States and in Europe (B lanch et al., 2006). Howe ver, for some specific tiered approaches in sanitary i nvestigations, certain chemical biomarkers of sources may provide timely or higher resolution information in fecal s ource tracking. Some of the most promising are

discussed below.

2.7.1 Fecal Sterols

The most commonly known f ecal sterol, coprostanol (5 β -cholestan-3 β -ol), is largely produced in the digestive tract of humans and dogs by micr obial hydrogenation of cholesterol (Leeming et al., 1996). The term “sterols” is generally used fo r all sterols and stanols (i.e., “fecal sterols”) and is also a more sp ecific term denoting a steroidal alc ohol with at least some degree of

unsaturation.

Two pathways have been proposed for the biotrans formation of cholesterol to coprostanol, one in the gut and the other in natural sediments. The α -configured form (cholestanol) is the most thermodynamically stable of the reduction products and is found ubiquitously in the environment; whereas coprostanol is largely of f ecal origin, but some reisomerization can yield

low levels in natural sediments. Both form s 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 absolu te concentration of at least f our of these related compounds to

attribute fecal source contributions between human s, 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 indica tive of a health risk due to multiple sources and low level environmental pr oduction in sediments.

The fecal sterol biomarker technique offers ma ny diagnostic and quantitative advantages when used in conjunction with traditional techniques for detecting sewage pollution. When careful data interpretation is undertaken, fecal ster ol analysis, although expe nsive and complex, has resolved problems of source attribution in urban and rural environments not possible with use of

traditional fecal indicator bacteria and coli phage 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 excr eted (Peeler et al., 2006). Most work in the past decade hasU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 50 focused on heavily polluted systems and efficiency of caffeine removal in sewage treatment plants, although with improvement s in techniques and the lowered detection limits, the scope of application has broadened to include stream, we tland, estuarine, and groundwater systems.

A major disadvantage is that caffeine is often pr esent 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 anal ysis) are relatively complex and expensive. Nonetheless, based on the recent work of Peeler et al. (2006) in sout hwest Georgia, caffeine appears immediately below wastewater discharg e sites and within towns, but not in rural watersheds. Overall, aquatic conc entrations of caffeine are typically less than for fecal sterols, but caffeine tends to stay in solution, whereas th e sterols associate with fine particulates.

2.7.3 Optical Brighteners and Other Sewage Markers

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

identification.

One relatively inexpensive and sensitive feca l source identification method is fluorometry (Hartel et al., 2007). Fluorometry identifies human fecal cont amination by detecting optical brighteners (also called fluores cent whitening agents) in wate r. 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 deterg ents contain optical brighteners (Hagedorn et al., 2005). Because household plumbing systems mix effluent from washing machines and toilets together, optical brighten ers 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 pl ant 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 with out accompanying data on viable fecal indicators does not provide information on the poten tial health risk from pathogens.

However, results of studies that have combined fluorometry with counts of fecal bacteria have been contradictory. Although various reports ha ve 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 (Harte l et al., 2007). One key confounder has been the presence of organic matter that fluoresces and interf eres with fluorometry. Yet, this interference can be reduced by adding a 436-nm emission f ilter 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 indica tor sampling combined with fluorometry can be a relatively inexpensive method for identifying human fecal contamination in water.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 51 In summary, chemical biomarkers appear to have niche applicability for those with the resources and expertise to use them and where such biomarke rs are advantageous, such as where other less expensive MST options have shown to be uns atisfactory 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 assa ys identify, and how they may relate to health outcomes for r ecreational exposures (a lso using archived epidemiological study material) ( high priority ).

a. Example priority list of organisms: enterococci, Bacteroides

, C. perfringens

, E.

coli , F+ RNA coliphages, and somatic coliphages

2. Investigate the potential for sp eciation of enterococci to identify fecal-specific (preferably human) from environmental strains, th en 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 ar e human-specific and validate their use over a range of geographic area s, 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 correlati ons for a range of pathogens/indicators (includi ng bacteriophages) from va rious 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 abse nce of human Norovirus-qPCR, adenovirus-qPCR, Pan-enterovirus-qPCR, polyoma viruses ( high priority ).

7. Conduct health and epidemiological studi es 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 tool s in sewage in order to determine the correlations of the occurrence of these pathoge ns 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 c ontributors to illness from swimming, there have not been prospective epidemiological studie s to actually support this association. Use serology (also c onsider collecting saliv a and possibly fecalU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 52 samples) to help identify the etiological agents from sewage that are impacting on recreational water sites ( high priority ).

a. Conduct similar studies in recreational wate rs (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 ad enovirus 40/41], but also JC virus, and Norovirus) in ambient waters ( medium priority ).

10. Determine if there are any appropriate sewage associated bacteria l 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 crite ria. 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 tr ansport studies to determ ine 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 viruse s (new or cyclic reemergence of viruses) and the efficacy of current indicator targets used by molecular

methods for health based correlations.

a. Develop predictive models to unders tand 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 fo r pathogens as a mean s of public health surveillance and informing pathogen m onitoring programs for CWA purposes.

4. Develop robust method for speciation of entero cocci with a view to identify fecal-specific (preferably human) from environmental stra ins; then apply to future MST and epidemiological studies (assumi ng initial studies suggest that this should be explored further).

5. Conduct studies on beaches to ch aracterize 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 id entify a range of pathogens/indicators from

various nonhuman sources of fecal contamination.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 53 References

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June 2007 57 

## C HAPTER 

## 3

M ETHODS 

## D EVELOPMENT

Stephen Weisberg , Chair, Southern California Co astal 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[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 59 3.1 Introduction

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

1. What are the attributes and cr iteria 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 wh ich those studies have been conducted and that are ready for adoption?

4. What studies (or modifications to planned studi es) 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 memb ers was recognition that the evaluation of

methods and/or indicators need s to be considered in contex t of the Clean Water Act (CWA) applications in which they would be used. Th e 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 to tal 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 te rminus of National Pollutant Discharge Elimination System (NPDES ) discharge pipes; and

• Trends assessments to determine whether wate r 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 curre nt recreational water quality criteria. However, several workgroup members also r ecognized the relevance of the ot her applications so a short section is included (see S ection 3.7) that illustrates the similari ties and differences in the method evaluation process for these other CWA uses.

For water quality notification systems, two princi pal issues were identified that need to be

addressed. The first is that current laborator y measurement methods require up to 24 hours to

enumerate indicator bacteria. Contaminated b eaches remain open during this processing period, but indicator bacteria may already have return ed to acceptable levels by the time laboratory results are available and warning signs are post ed. Continued advances and improvements in molecular- and immunological-based techni ques provide new opportunities for measuring bacteria more rapidly. Although current (traditional/standard) met hods rely on bacterial growth and metabolic activity, these new methods allow di rect measurement of cellular attributes, such as genetic material or surface immunological properties. By el iminating the necessity for a lengthy incubation step, some of th ese methods have the potential to provide results in less than 4 hours, enabling managers to take action to prot ect public health (i.e., post warnings or close beaches) on the same day that water samples are collected. This assumes that samples can beU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 60 processed at the beach or that the time required fo r 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 member s 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 thes e sources is responsible for th e measured enterococci. As such, existing warning systems do not provide an equal level of health risk protection at all beaches. Moreover, the costly cleanup processe s associated with the TMDL programs are not necessarily focused on the beaches that represent the greatest publ ic health risk. There are additional concerns that cleanup ac tivities, 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 framewor k to address one-size-fits-all concerns. The first adjustment is to develop add itional 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 speci fic to human sources and better related to human health risk than the existing indicator.

The second potential adjustment is to adopt a fr amework similar to that of the World Health Organization (WHO, 2003), in which watershed char acterization studies are used to adopt sitespecific standards. These site-specific standard s 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 evaluati on 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) replacemen t of existing indicato rs 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 deve lopment of site-specific standards. Within each section, the adequacy of evalua tions of methods/indicators is di scussed and the most immediate

research activities that woul d provide the greatest benefit to EPA for modifying monitoring

and/or indicators within the ne xt 5 years are highlighted.

3.2 Classes of Indicators

The evaluation of methods is a critical element in bringing ne w technology to the measurement of water quality. Current evaluation protoc ols were developed for cultural methods for enumerating bacterial indicators of fecal contam ination. The evaluation usually included methodU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 61 attributes regarding the performance of the me thod, such as specificity, accuracy, and precision.

Further evaluation that addressed how the me thod 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 usef ul results?). The quest ion that arises is whether the current protocols for evaluating memb rane filter culture-based methods are suitable for evaluating new methods that are being propos ed for measuring water quality. Some of the new or alternative methodologies that are available for testing water quality include molecularbased 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 ar e “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, enzymebased methods measure substrate utilizatio n employing compounds that fluoresce when metabolized by specific bacteria. Comparison of the fluorescence to a standard curve allows a

“count” to be established. A nother method measures adenosin e triphosphate (ATP) using a bioluminescence measuring instrument to determ ine the amount of ATP that is produced only

from viable bacteria.

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

Leading candidates are i ndicators and detection methods that can be used to replace current culture-based indicators of water quality (i.e., enterococci and E. 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 performanc e of this method have been completed. As described above, enterococci have also been qua ntified using a fiber op tic/fluorescent antibody detection method, an enzymatic/substrate method, and a method that measures ATP. None of the latter methods have been evaluated with respec t to either their perfor mance characteristics or for robustness. Similarly, molecular-based me thods that measure viruses (e.g., adenoviruses) that might replace currently used indicators of recreational water qual ity have not had their performance evaluated. If these indicators are s hown to be effective in their performance, they will be candidates for use in epidemiological st udies to determine how well their densities in

recreational waters relate to swimmer health.

Another class of microbes and other analytes are related to identifyi ng 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 ha s 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 alsoU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 62 Chapter 2). Optical brighteners are measured quite easily with a spectrofluorometer, while caffeine, coprostanol, and urobilin require mo re complex instrumentation, such as a high performance liquid chromatography (HPLC) instru ment. 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 diffe rent characteristics of these s ource specific analytes. For instance, the range of applicability and practicalit y 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 previous ly, 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 poten tial indicators may be candidates because they are species within a gr oup indicator, such as th e enterococci and clos tridia, and individual species may better indicate the qua lity of a waterbody. It is likely that this class of indicator will fit well into the current paradigm for characte rizing 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 passe s defined performance criteria, it must be evaluated for its application as an equivalent (o r superior) water quality tool compared to the current assays. An example of when this appro ach might be used is the transition from culturebased enterococci detection to detecti on 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 relations hip to health risk is the best approach to evaluating a new method. An epidemiological st udy 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 a nd will therefore be more protective of public health than the current approach that relies on indicator detection. Likewise, if the ne w method offers other improvements over the existing method (e.g., more rapi d, less costly, etc.), then its relationship

with human health should be at leas t 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 exam ple, a culture-based en terococci assay does not measure the same thing as a polymerase chai n 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 appr opriate or possible.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 63 3.3.2 Establishing Equivalency between New and Standard Methods

The equivalency validation approach assumes that for methods with simila r 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 h ealth risk directly. Given the cost and time involved in large scale epidemiological studies, the equivalenc y approach can be performed for many new

methods. The EPA should determine how dissim ilar the method targets can be and still be evaluated by this approach. For example, ce llular activity-based assays (e.g., immunomagnetic separation and ATP bioluminescence [IMS/ATP]) and membrane-filtration assays both measure viable cells, even though the e nd points are different. The workgroup members suggested that this activity-based assay is si milar enough to be eval uated through equivalenc y 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 Alternat e Test Procedure (ATP) Protocol for Drinking Water, Ambient Wa ter, 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 appr oved method (the “gold standard”) for 80% of the matrices tested. Currently, only culture-based methods can be in cluded 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 equivale ncy validation between me thods 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 guide lines for comparing between methods. Similar to EPA, this validation compares method performance between multiple sample types and laboratories and also sets ac ceptable variability between results at 0.5 log (based on within method variabil ity previously reported [Griffith et al., 2006; N oble 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 pres criptive because it disallows applications for methods that are not culture-ba sed. In the future, for example, should the IMSATP test be found to have a health risk-based association, EPA should consider allowing its comparison to culture-based methods since both a ssay for live organisms, albeit not exactly via the same mechanism (membrane-filtration coloni es or Most Probable Number [MPN] results versus ATP occurrence). By the same toke n, 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), th is 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 approach es is chosen (health risk-based or method equivalency-based), performance criteria for th e method should be comp leted, and preferably before using the method in an epidemiological st udy to obtain heath risk-based association data.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 64 Workgroup members consider the following to be the major parts of performance criteria: repeatability, accuracy, specificity, sensitiv ity, 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 re gard 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 plac e. 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 e xpressed both on an absolute scale (i.e., standard deviation) and on a relative scal e (i.e., relative standard deviati on [RSD]). The RSD (sometimes referred to as coefficient of variation) is calc ulated 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 appropr iate for summarizing precision when variability increases as concentra tion 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 systema tic 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 ne gative 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 th e target organism by the analyst when compared

to the reference method. To assess whether th e false positive rates are significant, replicates known to contain non-target organi sms that could be falsely iden tified as the target organism should be analyzed. The determination that th e samples do not contain the target organism should be based on a third independent standard me thod. For example, if the target organism is

cultured E. coli , the test should be used against, at a minimum, other enterobacteria, and, depending on what the test is, potentially Gram pos itive organisms as well. If the test is for genetic material, then the prim ers and probes should be tested against GenBank to look for potential false positives from non- E. coli species with the same sequences. Specificity also asks the false negative question regard ing whether the new method is si gnificantly 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 fa lse negative rates are significantly different between me thods, replicates known to contai n target organisms should be analyzed. As in false positive studies, the de termination that the samples do not contain the target organism should be based on a third inde pendent standard method. For example, if the target organism is genetic material from E. coli , then a method for culturable E. coli can be used.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 65 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) × 100%; and

2. false negative rate = # false negatives/(# true positives + fa lse negatives) × 100%.

The sensitivity of a test is the an alytical 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 sing le measurement with a stated confidence level. Generally, these refer to instrume nt analysis; thus, it is th e lowest quantity of a substance that can be distinguished from the absence of that subs tance (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 confid ence around that level is lower and more subject to user error.

The robustness of a test is th e 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 performe d 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 organism s)? Robustness is not a measurable attribute per

se but must be considered and a pplied 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 rang e of applicability does not apply to matrices other than the one for whic h the test was designed; that is, a recreational water quality method should not be expected to perform equally we ll 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 consider ed important enough to be menti oned here—capital cost, training cost, per sample cost, and additional sampling re quirements. Capital co sts include the upfront costs such as equipment purchase and the actual sp ace required for the test. For example, when performing genetic testing, aside from the equipm ent needed (e.g., platform [specific machine], laminar flow hoods, dedicated pipettors), space is needed, ideally in separate rooms, for reagent preparation (material not containi ng any genetic materials). Sp ace is also needed for the two types of sample preparation, t hose containing high target sequen ce DNA concentrations such as DNA standards and calibrator samples, and those containing expected low target sequence DNA concentrations (e.g., filter blanks and water sa mples)—the latter of which should also be inU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 66 separate laminar flow hoods. Training costs are thos e incurred prior to routine testing so that the user can perform the test within the performa nce criteria of the test; these may include participation in a workshop for hands-on experien ce 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 comp leted on a routine basis. Add itional sampling is generally an effort that results from rapid testing. For exam ple, 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 Al ternative (New) Indicators

Currently, recreational wate r quality is assessed with a single indicator with a single threshold (i.e., a “one-size-fits-all” appro ach). Under consideration is the implementation of alternative indicator(s) that are better asso ciated with human health risk than the enterococci. These

alternative indicators could theore tically replace the current standa rd but still be used in a onesize-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 fina l 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, a lthough 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 posit ive/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 cr iteria, including:

o relationships to health risks must be es tablished based on epidemiological studies covering an array of beach type s 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 67 3.6 Evaluating Source Identification Methods – Proficie ncy 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 identi fy 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 manage rs in implementation of best management practices (BMPs) that can redu ce 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 surf ace waters across the wo rld (Blanch et al., 2006; Stoeckel and Harwood, 2007). Although there has been significant progress in the MST field over the past decade, variability among performan ce measurements and validation approaches in laboratory and field studies has le d to a body of literature that is very difficu lt to interpret, both for scientists and for end users (Stewart et al., 20 03; 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 project s need to include some considerations for representative sampling, sampling frequency, sa mple volumes required, and the number and choice of source categories. Alt hough the use of a toolbox appro ach has been important in MST studies, there is a desire to deve lop an appropriate tiered approach to avoid costs and time from using multiple methods simultaneously. Within th e MST community, and larg ely as a result of the method comparison studies, library-independen t methods are currently the priority, while chemical-based methods appear to be desirabl e for rapid screening an d presence-absence tests (with perhaps quantificati on in the future). Library-based met hods still have a role in MST, but only in those circumstances where detailed info rmation is needed, such as many TMDL-based

studies.

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

Examples (not comprehensive) include both molecular approaches ( Bacteroidales

, E. coli toxin, Enterococcus Esp gene, direct measurement of source-specif ic 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 follo wing 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 b lind 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 lim it 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;U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 68 6. The reproducibility of analytical resu lts, both inter- and intra-laboratory;

7. The suitability of marker detection (and/o r quantification) to meet study-specific objectives; and

8. Detection of several of the a bove, 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, optic al brighteners, hostderived DNA (e.g., eukaryotic mitochondrial DNA), f ecal sterols/stanols, and source-specific fecal compounds such as caffeine and pharmaceuticals for humans.

The performance criteria in numbers 1 throug h 8 above, excluding #4 and #5, apply to nonmicrobial 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 diffe rent 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 a ddition, the following four criteria apply:

1. Jackknife (also reported as holdout or cross-validation) an alysis 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 re duce redundancy, based on the precision of the typing method;

3. External proficiency or blind tests to dete rmine both size and repr esentativeness 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 th e external proficienc y (or blind) set.

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

Indicators are used in many diffe rent contexts. Routine beach m onitoring, the most time-critical

use of indicator bacteria is desc ribed extensively in other chapte rs of these proceedings. This section briefly addresses other (seco ndary) uses of indicato rs. 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 crite ria. It is important that th e methods be highly specific and robust. Because of the potential for illness in exposed populations, it is extremely important thatU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 69 this use of an indicator be associated with grea t specificity and robustness. Specificity in this case refers to the ability of a method to detect an indicator with certainty that th e 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 microbe s 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 unaccep table 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 wh ere the correct result must be obtained in a very short time period.

Another use of indicators is for compliance m onitoring purposes, such as monitoring sewage treatment effluent for EPA’s NPDES Program. Im portant characteristics for indicators used for such compliance monitoring are precision and speci ficity. The precision is necessary because sewage treatment plants would receive a fine(s) if limits of the permit are exceeded. The specificity, both false negative and false positiv e responses, are important for the same reason mentioned above and may influence the way beaches are managed.

Trend assessments are used to determine whethe r water quality conditions at a site are changing with time. The most important characteristic is pr ecision that contributes to the ability to detect small changes over time (i.e., whether the water qua lity 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 indicato rs, (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 feasibili ty of implementation in near-ter m (1 to 3 years) and mid-term (2 to 5 years) or longer timefra mes. Although these are listed in priority order, the workgroup members felt that they largely expand on efforts th at EPA or its potential partners have already

initiated and all are achievable in the next 3 years. Appendix G summa rizes currently planned measurements for use in the upcoming Doheny and Malibu Beach (California) epidemiology study.

1. Systematic evaluation of performance cr iteria for library-independent source identification methods (for use in source ch aracterization [i.e., hum an versus nonhuman fecal contamination] and in MST) (timeline: 1 to 2 years).

Workgroup members felt that EPA should fast-tr ack studies to evalua te 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. St udies should include samples spiked with known source fecal matter from multiple host s as well as environmental samplesU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 70 collected from areas with known dominant sources of f ecal contamination. Samples should be assayed by the test methods in several laboratori es 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 follo wing 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 ( nifH gene);

5. Clostridium perfringens ;

6. coliphage; and

7. Bacteroides human-specific markers.

The last two methods are also being planne d for use in EPA’s upcoming (2007) health risk (epidemiological) study. The workgroup members fe lt 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 geogr aphic areas, candidate methods should also be evaluated from the perspec tive of persistence of geneti c 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 manageme nt-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 indi cators 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. Coordinate d studies to evaluate the performance criteria over multiple labs ar e needed to implement these assays.

The following analytes should be include d in near term evaluation studies:

1. optical brighteners;

2. coprostanol; and

3. caffeine.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 71 At least one multi-laboratroy evaluation study of optical brighteners is currently being developed by individual invest igators (Hartel et al., 2007).

3. Continued evaluation of rapid a ssays for the detecti on of enterococci in human health risk (epidemiological) studies (tim eline: 1 year and beyond).

Rapid detection of current water quality i ndicators 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 ne eded before implementation. Additionally, other rapid assays for enterococci have b een developed and should be evaluated in upcoming and future epidemiological studies.

Methods under consideration for entero cocci detection include the following:

Immediate (timeline: 1 to 2 years):

• qPCR (detection of DNA); and

• TMA (detection of RNA).
Mid-term (timeline: >2 years; requ ire additional performance evaluation):

• IMS/ATP (detection of activity);

• RAPTOR TM (antibody-based detection) 5 ; and

• enzymatic detection.

4. Evaluation of alternate indicat or candidates in human hea lth 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 relati onship with health risk.

The following indicators should be eval uated within the next two years:

• Bacteriodales human specific markers; and

• F+ coliphage (antibody).

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

5. Optimization of sampling, recovery, and proces sing methods for efficient concentration, processing and detection of rapi d, alternative or host specific indicators (Time line: 1 year and beyond).

5 http://www.resrchintl.com/raptor-detection-system.htmlU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 72 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 (esp ecially for targets e xpected to occur at low numbers in the environment).

Furthermore, research addressing stra ightforward 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; M uniesa, M; Schwartzbrod, J; Skraber, S; Papageorgiou, GT; Taylor, H; Wallis, J; Jofre, J. 2006. Integrated analysis of established and

novel microbial and chemical met hods 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 fo r detecting human fecal contamination. Water Research: In press.

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

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

Stewart, JR; Ellender, RD ; Gooch, JA; Jiang, S; Myoda, SP; Weisberg, SB. 2003.

Recommendations for microbial source tracking: Lessons learne d from a methods comparison study. Journal of Water and Health 1: 225-31.

Stoeckel, DM; Mathes, MV; Hyer, KE; Hagedorn, C; Kator, H; Luka sik, J; O’Brien, TL; Fenger, TW; Samadpour, M; Strickler, KM; Wiggins, BA. 2004. Comparison of seven protocols to identify fecal contamination sources using Escherichia coli

. Environmental Science and Technology 38: 6109-6117.

Stoeckel, DM; Harwood, VJ. 2007. Performance, de sign and analysis in microbial source tracking studies. Applied and Environm ental Microbiology 73(8): 2405-2415.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 73 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 Pr ocedure (ATP) Protocol for Drinking Water, Ambient Water, and Wastewat er Monitoring Me thods – 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.[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 75 

## C HAPTER 

## 4

C OMPARING 

## R ISK 

## ( TO 

## H UMANS 

## ) FROM 

## D IFFERENT 

## S OURCES

Dennis Juranek , Chair, Centers for Disease Co ntrol 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[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 77 4.1 Introduction

Fresh and marine recreational waters and beac hes may be impacted by human and/or animal feces from point and non-point sources. Stud ies have recently been completed by EPA on assessing rapid water quality indi cators and their ability to pr edict swimming-associated illness at freshwater beaches impact ed by publicly (and privately) owned (sewage/wastewater) treatment works (POTW) systems. Similar EPA studies are currently pl anned (starting summer of 2007) to assess the risk of illn ess for people who swim in marine recreational waters impacted by POTW systems (point sources of fecal contamin ation). 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 th e Southern California Coastal Water Research Project to assess swimming risks at least one mari ne 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 ex clusively (or primarily) impacted by feces from animals. The absence of such da ta 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 larg er health risk than an imal 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 infect ious to other humans, while relatively few of the enteric pathogens of anim als are infectious to humans. Possible exceptions are bird flu virus and swine hepatitis E virus (HEV). Wo rkgroup members regarded the evidence for swine HEV transmission by water to be ve ry weak and felt that it could disregarded in terms of risk assessments during the next 2 to 3 year EPA pla nning 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 he alth 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 ri sk is recognition that animals do harbor many bacterial and protozoan pathogen s 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 de monstrate 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 differen ce in order for EPA to make appropriate public health recommendations. The only way to get a be tter sense of the health risk for swimmers posed by animal feces is to conduct targeted studie s. Some types of studies (epidemiological and quantitative microbial risk asse ssment [QMRA] studies) would pr oduce quantitative estimates of risks while others (fate and transport, pathoge n loads in water, etc.) would provide supporting information or stand alone qualita tive information about risk.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 78 It is recognized that there are many different types of animals a nd that the pathog en 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 ri sk. Workgroup members approached the issue by developing Table 5 in order to rank the likely risk s 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 univers e of pathogen sources of interest to recreational waters. Workgroup me mbers 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 sedi ments). The wildlife row is subdivided into aquatic birds and all others. The agricultural an imals 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 Huma ns) from Different Pathogen Sources. a

Source Viruses Protozoa Bacteria

Wildlife
Aquatic birds N L L-M Other (e.g., deer) N M M #2 priority
Agricultural animals
Poultry N N M-H Other (e.g., cattle, sheep) N M M-H #1 priority

Domestic animals
Pets (e.g., dogs, cats) N L L
Fecal shedding by bathers #3 priority

Adults L L L

Children H H H
Sewage No treatment (combined sewer overflows) H H H No treatment (separate storm sewer overflows) ?* ?* ?*

Secondary treatment** H H M

Plus chlorine** H H L

Plus UV M-H (L with

increased energy) L

Secondary environments *** L L M

a Does not have an explicit fate and transport component * Risk largely depends on am ount of human feces present ** Focus of most (U.S.) recreational water epidemiological studies *** Sediment suspension an d contact with beach sand

N = estimated no or negligible risk, L = estimated low risk, M = estimated medium risk, H = estimated high riskU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 79 into untreated sewage, secondary treatment sewage, chlorinated sewage, and UV-treated sewage. Fecal shedding by bathers (adults and child ren) is considered separately.

The columns are defined by broad microorganism gr oups 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 ri sk (N), low, medium, and hi gh (L, M, H). The types of

characteristics discussed included infectious dose, numbers of pat hogens per gram of stool from infected animals, implication of source in wa terborne disease (exte nded discussion on foodborne disease and vector-borne disease), persistence a nd 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 repr esent the workgroup’s “bes t guesses” and assumed that animal feces was deposited in freshwater rela tively 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 so il to water affects on viability, etc.). It was felt that many of these t ypes of data are available and that the table could be updated with real data at a la ter 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 ri sk (indicated by “N” entries in Table 5). All the human sources were given a high risk estimate with the exception of UV-treated sewage. UVtreated sewage at curren t 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 ad enoviruses. 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 an imal 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-m edium and again, the human sources were all assigned a high ranking with excep tion of chlorine- and UV-treated sewage that received a low risk ranking.

Bather density was divided into adults and childr en (recognizing that chil dren 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 ad ults. Thus, for adults, a low risk ranking was assigned across the columns and a high ri sk ranking was assigned for children.

Based on the few studies done on secondary envir onments, viruses and pr otozoa were given a low risk rating, while bacteria were given a medium rating.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 80 In developing Table 5, workgroup members noted the following discussion points:

1. Current epidemiological literature suggests that the symptomatic profile of swimmingassociated illnesses indicate s 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 sugge sted 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 s uggested that they could have a human component in many communities.

In discussing the future research needs related to the development of ne w or revised recreational water quality criteria, the wor kgroup members defined the ultima te 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 sewa ge row that is currently the focus of recently completed EPA National Epidemiological and Environmental Assessme nt 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 wate rborne 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 cla ssification of waterways as impaired. The

discussions were wide-ra nging. Discussions began with the c onsideration of the relationship of

likelihood of illness due to nonhuman sources to likelihood of illness predicted by the use of epidemiological data from huma n exposure to POTW-impacted wate rs using fecal indicators. Possible approaches to modifying the application of regulatory appr oach using considerations of infectivity to pathogens among species were debate d. The location of feca l 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 pot ential 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 i ssues for consideration. A brie f synopsis of responses to the questions is presented below.

• Question 1: Is setting criter ia based on a treated human poi nt source such as a POTW protective, under-protective or overprotecti ve of other potential sources of human pathogen? Why or why not? Are there data to support this conclusion?U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 81 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 sens e of security for protoz oa and viruses. This reflects the higher degree of effectiveness of chlo rine in killing/deactivating bacteria relative to viruses and protozoa. Given th at current indicators are bacter ia and would be reduced to a greater extent than viruses and protozoa, low indi cator levels might suggest that waters impacted by POTWs were relatively pathogen-free when th ey still contained a significant virus and protozoan load. Data are available to characte rize the relative effect iveness of disinfection techniques across classes of waterborne pathogens and indicator organisms.

• Question 2: Based on the “state of the sc ience,” 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 ris k. 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 th e 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 lite rature (Haile et al ., 1999) noting the occurrence of a significant occurrence of human pathogenic viruses in stormw ater effluent and associated health effects merits further investigation. A quatic avian sources were consider ed 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 es timates 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 reflec ted in the responses to Questions 1 and 2 above. The propensity to over- or unde r-protect would depend upon the s ource of the waste impacting the site. Non-point sources that largely refl ect nonhuman sources of fecal contamination would probably be overprotected by studi es in POTW-impacted locations. Mixed sources or untreated human sources may be inappropriately charac terized by the POTW-dominated data. The workgroup’s generalizations are re flected 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 char acteristics. Although the im portance of dilution of pathogens and indicator organisms in runoff ev ents was discussed, no conclusion was reached about its significance.

6 It is important to note that the workgroup was specifi cally 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 82 • Question 4: Assess whether there is a possibi lity 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 eval uate risk that may have a lo w 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 w ith severe health outcomes. However, this important public health issue might be addresse d using quantitative microbial ri sk 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 ar e presented in a separate section (4.4). Epidemiological studies were gi ven a high priority, with QMRA as an important adjunct. Additional epidemiological studies were enc ouraged 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 st udies 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 epidemiol ogical study. If suitabl e sites cannot be found, then modeling the risk using QMRA techniques ba sed 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 Ta ble 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 ar e applicable to bot h the European Union (EP/CEU, 2006) and WHO (2003) approaches to criteria development. The sanitary i nvestigations are important for the topics discussed by this workgroup. Simulta neous use of multiple indicator organisms or a tiered approach may be necessary.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 83 4.4 Research Needs

1. Prioritize the next genera tion of studies. The purpose of th ese studies is to (1) revisit the ratings using a more through literature revi ew and (2) gain as much information as currently exists on the magnitude of the f ecal pathogen source problem across the United

States.

a. Quantify the magnitude of difference in th e 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 in fectious 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 th e sources (number of affected bathers if available)

iii. Identify potential fresh and marine recr eational 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 a nd 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-speci fic) about pathogen loads in non-point source water impacted by all sources of fecal contamination (human and animal), charac terizing 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 sw imming in fecally contaminated waters. Although many epidemiological studies have been previous ly 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 indi cators and health outcomes that is currently used in regulating beaches was developed from studies at point source-impacted beaches where water quality indicator levels co rrelated with swimming-associated illness (US EPA, 1986). It is plausible that the relati onship between water quality indicato rs and health is different at nonpoint 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 conduc t epidemiological studies at non-point sourceimpacted sites to better define risk and guide future regulations.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 84 Some workgroup members noted that epidemiological studies cannot be performed in all of the various types of non-point source-imp acted 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 site s (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 co ncentrations of pathogens pres ent, 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 re strictions 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 observationa l cohort. The RCT has been primarily used in European studies and the obs ervational 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 coul d 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 stud y 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 recrui ted and enrolled in the studies at sites distant from the beach and then brought to the study sites. Workgr oup 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 nonpoint source sites where adequate numbers of swimmers could be enrolled, the prospective cohort design could be used for epidemiological studies. Workgroup memb ers felt that it would be very helpful at some point to use both st udy 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 st udies at beaches impacted by different types of non-point sources of fecal contamination [see Table 5] )

a. Randomized control trials (for consider ation at beaches with low numbers of bathers)

i. European design should be modifi ed for use in the United States (suggestion – randomize people about to swim into groups that will swim or not swim)

ii. Potential problem – identifying appropr iate numbers of participants may be more difficult for inland (predominantly fresh) recreational waters than

marine waters

iii. Estimated necessary samp le size – 1,500 people/site

b. Prospective observational cohort study

i. Potential problem – identifying sufficien t numbers of participants may be

more difficult for inland recreational waters than marine watersU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 85 ii. Estimated necessary sample size – 5,000 to 10,000 people/s ite (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 informa tion is available. QMRA studies can also be

instructive in recreational areas where such studies have already been completed.

QMRA is increasingly used to ch aracterize risk to humans from exposure to contaminated water when engaging in “contact recreation,” especia lly swimming, but also other forms of water contact such as water skiing. It translates the environmental o ccurrence of pathogens and the

volume of water that individuals ar e exposed to into a probability of infection or illness. Inputs with known variability are desc ribed by statistical distribu tions from which many random samples are taken, often using a “M onte Carlo” calculation procedur e, to derive a risk profile. 7

The following four step process is used: (1) id entifying the important pa thogens (“hazards”); (2) determining human exposures to contaminated water, via ingesti on or inhalation; (3) characterizing dose-response, using data available from clinical trials, illness surveillance, and outbreak data; and (4) mathematically charac terizing 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 illnes ses that could arise in the United States, such as the following:

• viruses – norovirus, Hepatitis A virus, ca liciviruses, enteroviruses, rotavirus, adenoviruses;

• bacteria – EHEC, Campylobacter spp., Salmonella spp., Shigella spp.; and

• protozoa – Giardia cysts, Cryptosporidium oocysts.

The setting for each site of inte rest will dictate which of these pathogens should be used. For example, a recreational site imp acted only by animal wastes should not need to include viruses.

Adenoviruses will need to be included where aer osols may be inhaled (e.g., by water skiers).

For step 2, information on water ingestion a nd exposure rates, along with duration of the recreational activity, are combined with the concentration of pathoge ns 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.ils i.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 wa ter-based media. Contact Stephen Schaub, EPA Office of Water (see Appendix B), for information on the Protocol for Microbial Risk Assessment.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 86 dose—all these variables being de scribed by statistical distributi ons. Information on the origin, quantity, and fate and transport of wastes depo sited 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 report ed 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 doseresponse equation, in the form of credible intervals, can be capt ured by the calculation process.

In step 4, risk profiles may be derived, in the form of a cumulative di stribution function—this will be particularly useful for examining the ri sks associated with rare but highly significant illness (e.g., EHEC). This also enables uncert ainty measures to be calculated. Comparing

relative risks for different site s should be done by comparing ri sk profiles, rather than by comparing single risk “numbers.”

1. QMRA provides a range of possible illnesses or risks, allows compar isons across all fecal pathogen sources (see Table 5), and number of illnesses by a modeling approach ( highest priority is to conduct assessments at be aches impacted by di fferent types of nonpoint 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, Campylobacter

, Salmonella

, Shigell a)

ii. Protozoa ( Giardia, 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 char acterize 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 pathog ens cause swimmer-associated illnesses at both non-point source- and point source -impacted beaches. Identificati on 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 87 revised recreational AWQC (or State Water Quality Standards) to enhance the protection of public health. In order to go forward with curre ntly available technol ogies, the diagnosis of viruses could be made by exclusion of bacterial and protozoan pathogens causes of illness. Additionally, such information wo uld be essential inputs into QM RA models to be used at recreational sites (or types of s ites) where epidemiological studi es cannot be conducted due to expense or insufficient numbers of swimmers. Because advances in modern techniques in microbiology now make a more complete iden tification of specific pathogens possible, workgroup members felt that the epidemiologi cal studies currently underway and planned provide a unique opportunity to collect specimens (st ool, saliva, and/or blood) from swimmers (and non-swimmers as controls) with which to id entify 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 ch apter and these proceedings. Workgroup members suggested that both types of pathogen occurrence information (i n 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 ag ents 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 techni ques (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 detecti on is not feasible on an ongoi ng basis, a surrogate measure relating water quality conditions to human health risk is required. When developing the appropriate indicator(s) to use in this ap proach, knowledge of the fate and transport characteristics of the pathogens and indicator(s), both individually and as th ey relate to each

other is critical.

Individually, fate and transport is significant be cause 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 tr ansport characteristics will vary (perhaps significantly) as well.

The most simplistic route of pathogen transpor t is direct deposition. Once the pathogen(s) (assumed to be carried in the f eces of warm blooded mammals) is excreted over or in the water, the question is twofold—how long w ill the pathogen be viable and available (i.e., persist in the water column).U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 88 Indirect deposition of feces introduces a more co mplex situation. First, the fecal properties of different mammals can vary substa ntially. 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 envi ronment. After defecati on, the distance of the feces from surface water plays an important role as well. Driven by prec ipitation and transported primarily via surface runoff, the pathogens are typi cally washed into the surface water either by sheet flow or are collected and discharged thro ugh a storm water collection system. During this transport, they are subjected to a variety of environmental fact ors—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 depo sition includes point source disc harges, such as POTWs, CSOs, concentrated animal feeding operations (CAFOs), and other NPDES permitees. In addition to the issues identified above, the effect of the treat ment processes that thes e effluents are subjected to plays a role in fate and transport of the pathogens.

Resuspension from sand, soil, or sediment (i .e., secondary environmen ts) can also play an important role in pathogen fate and transport. There may be a reservoi r of indicator(s) and/or pathogens that could be reintroduced into the wate r column. Additionally, re growth of either the indicator(s) or pathogens could repres ent 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 th e concentration of the viable pathogens in the water and ultimately to public health risk.

A number of studies have b een published on the fate and transport of many waterborne pathogens and current indicator organisms. Theref ore, a literature review to identify any data gaps so that additional studies may be designed and also to info rm QMRA studies would also be

useful.

1. Conduct fate and transport studies for indi cators 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 character istics as pathogens.

4. Should include assessment of risk of pathogens and indica tors being resuspended from sand, soil, and sediments (secondary environments).

4.4.5 Determine the Occurrence of Pathoge ns in Impacted Recreational Waters

The pathogen occurrence and pathogen concentrati ons in water impaired by animal feces in one or more non-point study site(s) (e.g., beach imp acted 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 cons ider using high-volume, tangential-flow water filtration me thods that were recently devel oped for assessing bioterrorismU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 89 threats to drinking water. Th is technology was designed to si multaneously capture very low concentrations of viruses, bact eria, 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 wate r, there has been additional research to adapt the process for use on raw water supplies. The ra w water application of this technology may be sufficiently understood for its employment in curre nt or planned studies w ithin the next 2 to 3 years. If the methods have not yet been adequa tely 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 ha ve serious health consequences (e.g., EHEC).

1. Determine the occurrence of pathogens in aff ected waters using the high volume filtration currently being developed for c ounter bioterrorism purposes.

4.4.6 Bather Studies

Bathers themselves can be a source of both in dicator organism and pa thogens 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 bath ers on levels of indicator organisms and as a source of infectious pa thogens for other bathers.

2. Develop better tools for assessing bather density.

3. Incorporate bather density into the study desi gn and analysis of futu re 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 indi cators and pathogens in QMRA studies.

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

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 m odeling 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 mode lers 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 observa tional epidemiologic st udies. The following would improve exposure assessment in epidemiologic studies:U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 90 a. Develop individual sampling devices.

b. Develop methods and conduct studies to de termine the quantity of water ingested and inhaled in recreational settings. Consider studying sec ondary recreational contact for potential comparison.

References

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

Elmir, SM; Wright, ME; Abdelzaher, A; So lo-Gabriele, HM; Fleming, LE; Miller, G; Rybolowik, M; Shih, M-TP; Pillai, 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/C ouncil 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 Re pealing Directive 76/160/EEC. Official Journal of the European

Union L64: 31-51. Available at: http://europa.eu.int/eurlex/lex/LexUri Serv/site/en/oj/2006 /l_064/l_06420060304en00370051.pdf.

Haile, RW; Witte, JS; Gold, M; Cressey, R; McGee, C; Millikan, RC; Gla sser, A; Harawa, N; Ervin, C; Harmon, P; Harper, J; Dermand, J; Al amillo, 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 In stitute 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 91 

## C HAPTER 

## 5

A CCEPTABLE 

## R ISK

Paul Hunter , Chair, University of East Anglia, U.K.

Michael Beach , Centers for Disease Control and Prevention Lora Fleming , University of Miami School of Medici ne and Rosenstiel School of Marine

and Atmospheric Sciences, Florida

Peter Teunis , RIVM (National Institute of Public H ealth and the Environment), Netherlands Timothy Wade , USEPA[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 93 5.1 Introduction

This workgroup was primarily charged to reassess the extent to which ex isting microbiological criteria protect the health of swimming populations, and whether or not this is appropriate for current U.S. society. In particular, the workgr oup was asked to consider the case of vulnerable (susceptible or sensitive) subpopulat ions and whether curr ent 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 dri nking 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 recrea tional 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 e ducate the general public about risks from

recreational water.

• “Acceptable risks” to the general population

o Whether the current methods for assessing ri sk from recreational water exposure are sufficient and if not, what new methods may be appropriate?

o Whether risks differ between marine and fres hwaters 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 prot ecting people from enteric illness is sufficient, or whether “acceptable risk” de cisions need to take into account nonenteric illness.

o Whether risks are different to people swimmi ng in tropical, subt ropical and temperate

waters.

• “Acceptable risks” for vulnerable subgroups

o Define the main vulnerabilities.

o Determine what risks are greater in vu lnerable subgroups and whether general

recreational water standa rds 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 me mbers that the term “acceptable risk” is flawed and should be avoided during the process of creating recreational wate r criteria. The termU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 94 “acceptable” was felt to elicit responses re lated 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 repl acing “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 ra ther than paternalistic in nature. Workgroup members also felt that EPA should develop a policy that includes public interaction during th e criteria development

process.

This approach to determining “acceptable risk” s hould 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 de velopment process should include information on how impacted groups would determine the leve l of “acceptable risk” and how those risks and the concept of protectiv e criteria would be best communicate d. This would require that EPA’s criteria development process (1) be clear, transp arent, and communicated to all stakeholders; (2) factor in and include input and data collected from impacted gr oups; (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 author ities with future communication of the concepts of “acceptable risk” and the meaning of beach clos ures and advisories to the public. Such an effort would require collaborati on with sociologists and anthropologi sts to assess risk perception

and risk communication research and apply this to development of appropriate assessment tools for determining key elements necessary for criter ia development, release, and interpretation. Rapid integration of this information into ongoi ng 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 woul d require that impacted groups are first informed about the process and then in formation solicited about how these groups make “acceptable risk” decisions and how tolerant thes e groups would be of ri sk associated with recreational swimming area use. Key research qu estions 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 doe s/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 wa ter 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 se tting 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 95 Workgroup members suggested that EP A 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 imp acted groups understand and perceive the risks

associated with recreational water use a nd 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 educati ng impacted groups about the new criteria.

4. Assist state and local officials in devel oping data-based risk communication plans for communicating information on criteria interpre tation and beach closur es/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 micr obial risk assessment (Q MRA) studies as the main methods for assessing risk. Some workgr oup members noted that while QMRA is widely used and relied on by EPA for drinking water applica tions, it does not seem to be as widely used for recreational waters (with th e exception of the work done by Jeffrey Soller). To broadly evaluate the gastrointest inal (GI) illness risk associated wi th the numerous potential pathogens found in recreational waters, epid emiological studies were viewed as more appropriate, although workgroup members believed the EPA should investig ate 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 associat ed with swimming in fecallycontaminated waters, they are not well-suited for investigating rare but potentially severe (and potentially life-threatening) illn esses 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 poten tial 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 specifi cally account for factors such as the immune status of the popula tion (susceptible, infected, immune), rates of secondary transmission of illness, and other parameters.

Workgroup members also noted that epidemiol ogical studies can iden tify illness, but not infections, whereas QMRA studies can predict inf ections, but have more unc ertainties associated with translating infect ions into an estimation of illness. Although epidemiological studies provide valuable results, there ma y be some confusion in their interpretation and application; for example, most studies of recrea tional 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 toU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 96 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. Alt hough 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 pe r 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 th at there could be different in dicators, or different levels

for the same indicator across mari ne 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 discussi on about how to account for differe nces in baseline levels of

illness that could exist across locales and whether us e 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 ve rsus doubling a relative risk (see Section 5.2.5).

Enteric versus Non-enteric

Workgroup members felt that criteria based on pa thogen indicator levels derived to protect against GI illness would not necessarily protect ag ainst all non-enteric illn esses, with the possible exception of certain upper respiratory illnesses (URI s) transmitted via the fecal-oral route. At least one study (Fleisher et al., 1996) observed exposure-response relationships with fecal streptococci (enterococci) an d URI; workgroup members believed there was potential for pathogens causing such illnesses (e.g., adenoviruse s) to be transmitted via fecally-contaminated waters. The workgroup members felt that most ca uses of other non-enteric illnesses (e.g., rash, earache) were most likely to be caused by environmental or na turally occurring conditions and/or pathogenic microorganisms unrelated to fecal contamination (e.g., Naegleria infection, noncholera 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 protec ting against such illnesse s, 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 in fections, 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 sw imming 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 theref ore AWQC or State Water Quality Standards based on fecal indicators woul d not afford public health protection forU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 97 those illnesses. Workgroup members also felt th at other indicator bacteria, or other types of indicators, are not currently av ailable to protect swimmers fr om most non-enteric illnesses.

Workgroup members agreed that when a beach wa s closed due to fecal contamination then potential non-enteric swimming associated illnesses would al so 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 indica tors correlate with the presence of cyanobacteria or

Pseudomonas ?).

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 temper ate waters because of issues such as regrowth and significant spatial or temporal variability of both indicator organism s and pathogens in the water and soils, substantially different ecosyst ems and climatic conditions (including heavy rains), and possibly the presence of a greater ra nge of “exotic” pathogens. In addition, persons may experience longer term seasonal exposures in tropical and subtropica l recreational waters due to the warm waters throughout the year. Fina lly, it is highly likely that the background rate of GI diseases is higher in tropical and subtropical populatio ns (Payment and Hunter, 2001).

It is important to note that wo rkgroup members believe that pe ople in tropical and subtropical areas should not be exposed to gr eater health risks from exposur e to recreational waters than people in more temperate areas.

Relative risk measures, unlike exce ss risks, express risk as a pr oportion 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. F ood and Drug Administra tion [FDA]). Workgroup

members felt that there was need for risk communi cation 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 disti nguished between two major categories of vulnerability, (1) persons at different life st ages, and (2) persons with suppressed immune

function.

What is Different?

Life stage connotes that for a variety of reasons, hu mans vary in their level of vulnerability to the health risks associated with expos ure to recreational water over their life span. In particular, the discussion focused on the possibl e increased vulnerability of children, pregnant women (and their fetuses), and the elderly. Workgroup members felt that children are at a greater increasedU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 98 risk compared to all other life stages because of their behavior and possibly because of naïve

immune status. Because all members of the population pass through life stages, classifying childhood as a life stage instead of simply a subpopulation st rengthens the argument for explicitly considering children when developing AWQC. Regarding behavi or, children probably have higher exposures; that is, they are more likely to consume both marine and freshwater. Moreover, young children have significant hand-to-m outh and fecal-oral behavior that may lead to the consumption of contaminated substa nces. Very young children may also be more vulnerable to pathogens in recreational waters b ecause 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 studie s appear to demonstrate an increased risk of GI illness and possibly respirat ory illness for children from e xposure to recreational waters, although this has not yet been formally reviewed.

Pregnant women (and their fetuses) and the elderl y may be at increased risk for more severe consequences from acquiring GI diseases from e xposure to recreational wa ters. Pregnant women and their fetuses may be at greater risk from cer tain recreational water pa thogens (e.g., coxsackie

B virus associated with fetal infection when acquired close to delivery, and enterovirus associated with certain fetal malformations). Fu rthermore, 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 wa ter. Finally, although the elderly were beli eved to be less exposed due to decreased high intensity swimming behavior, it might be possible that the

decreased immune function associat ed with increasing age might ma ke them more vulnerable to

infection and illness.

Workgroup members also identified a potentially large subpopulation of pe rsons with suppressed immune function, ranging from persons with HIV/AIDS to persons undergoing chemotherapy and using other immunosuppressive medications. Of note, a portion of th e latter subpopulation could be completely unaware of their suppressed immune func tion. 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 ri sk of more severe consequences from these diseases as well as from the effects of dehydr ation—a secondary ramification of GI diseases.

Tourists and visitors were identified by workgr oup members as a unique potentially vulnerable group to increased health risks associated with e xposures to recreational wa ters. Similar to small children, these people may be pr eviously unexposed to the range of pathogens in a new recreational water environment, a nd 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 great er exposure to recreational waters. 9 Further, given that significant tourist travel is to tropical and subt ropical areas, there may be additional risks from a range of exotic pathogens and potentially uni que 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 99 Overall, workgroup members believed that the appa rent increased risk for children for acquiring GI and possibly other diseases from exposure to bo th fresh and marine recr eational 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 recrea tional water criteria se t on health risks and exposures of adults would not be sufficiently pr otective 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 equa lly. The workgroup members felt that data on children should be explicitly considered for deriving the “acceptable risk” level in the development of new or revise d recreational water quality criter ia, with the understanding that

the associated risk level for adults would then be even lower.

Workgroup members felt that the in creased risk to immunosuppre ssed 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 wate r sites. Rather, an emphasis should be made on improved risk communication with immunosuppr essed groups and health care professionals

to inform them about risks associated with recr eational water use and, in consultation with their health care provider, assessment of the need to avoid recreationa l water exposure.

5.2.5 What are the Current Levels of Pr otection 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 sw immers can “take on a life of their own,” increasing the risk of distraction from the basic objective—providi ng 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 Resear ch 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 esta blished in 1986 also may have different susceptibility due to differences in immunity to current pa thogens in 1986 versus 2007. Aside from protec tion against enteric illnesses, it seems likely th at enterococci

levels below current standards also provide some protection against upper respiratory tract

infections.

Instead of absolute levels of risk, workgroup memb ers felt that the preventable fraction is a better measure for the level of protection. This incl udes 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 be neficial effects of lowering risks due to recreational bathing. Thus, an absolute reductio n in illness from recreat ional 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 ha nd, disease reduction may be even greater if secondary cases are also preven ted. Most recreational water exposures are experienced by a minority of the population who are re peatedly (chronically) exposed.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 100It is also possible that part of the primary contact-associated infections is caused by bather-tobather transmission. This independent, dir ect fecal contamination would be unaffected by monitoring programs designed to limit sewage c ontamination. Further st udies are needed to understand the role of bather shedding in dis ease transmission and mi crobial 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 th an 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 Protecti on 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 cr iteria that led to improved public health protecti on would not negatively impact on the risks from drinking water or shellfish consumption. However, some wo rkgroup members did expr ess concern about any change that would encourage furt her recreation in waters intended to be used for drinking water production or for shellfish harvesting. When peop le bathe they invariably contaminate the water to some extent with potential pathogens. Such pathogens may then be concentrated within shellfish or contaminate drinking water s upplies and pose a health risk to others.

5.2.7 Areas of Discord

Although workgroup members accepted that the phras e “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 al l 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 evaluat e the risk communication strategy

a. Assess public understanding of rela tive 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 in terpret existing criteria and beach closures/advisories? (4) How does/shoul d EPA communicate th is risk? and (5) What level of risk would the public accept?

2. Define the data and conditions where a di rected monitoring program would be necessary to protect agai nst certain non-enteric (non-GI) illness.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 101 a. Such research would probably require pa thogen-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-threaten ing) 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 mode ling for special/outbr eak 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 situa tions with rare, but potentially severe

outcomes.

4. Conduct methodologic comparisons in tropica l and subtropical recreational waters and if appropriate, conduct ep idemiological studies.
Methodological and ecological st udies 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 pat hogens in the water and soils, substantially different ecosystems and climatic conditions (including heavy ra ins), 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. Depe nding on the results of these studies, assessment of the need for epidemiologic studi es specifically in tr opical 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. Informati on on risks in such waters will help ensure appropriate risk communication to healthcar e providers, public and environmental health managers, and residents of and visitors to tropical and subtropical areas concerning the risks of tropical and subt ropical recreational waters.

5. Ensure that future epidemiological studie s 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 suffici ent protection to child ren then additional

information will be needed to establish new or revised criteria that are thought to provide sufficient protection. Such information will al so be essential to provide risk information to parents and others responsible for children.

6. Review prior data to evaluate whether addition al epidemiological studies are needed to determine the risk of severe disease to pregna nt women and their fetuses, to the elderly, and to immunosuppressed individuals.
There is evidence that pregnant wome n (and their fetuses), the elderly, and immunosuppressed people may suffer more seri ous disease and/or more serious healthU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 102 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 visi tors differ from those in residents.
There is some evidence that risk may be greate r for tourists and visitors than for residents local to a recreational water; thus, current es timates may underestimate the actual risk and so give inappropriately lax cr iteria (Payment and Hunter, 20 01). Consideration should be given to the design and implementation of futu re 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 touris ts. Information on risks in such waters will help ensure appropriate risk communica tion to healthcare providers, public, and environmental health managers, and touris ts with exposure to recreational waters.

8. Ecology of swimming-related waterborne path ogens, including studies on the role of bather shedding on transmission of illnes s and microbial water quality indicators

Further studies are needed to understand the role of bather shedding in disease transmission and microbial water quality indi cator levels. How efficiently are pathogens transmitted through swimming or bathing? This could be an experimental study, partly, augmented by epidemiology (serology, or micr obial 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, th e procedures/modeling assumptions should be agreed upon. It could be done relativ ely easily in a QMRA-type of study.

Table 6 provides a summary of how each workgr oup 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 103 Table 6. Research Needs and Rankings from Five “Acceptable Risk” Workgroup Members.

Description Importance Relevance to EPA Near- and/or Long-term
Conduct risk perceptio n studies to inform the risk communication strategy for the criteria rollout and focus groups to evaluate the risk communication strategy (#1) 5 5 5 5 5 5 5 5 5 5 N and

L N N N N Assess public understanding of relative versus absolute risk (#1) 1 2 1 3 3 1 1 1 3 3 N and

L N N N L Define the data and conditions where a directed monitoring program would benecessary to protect against certain nonenteric (non-GI) illness (#2) 3 3 2 3 3 3 3 2 3 3 N and

L N L N L Define data needed for the QMRA modeling for special/outbreak cases also for the background/regular situation (#3) 3 4 3 3 5 3 4 3 3 5 N and

L L N N N Engage QMRA in recreational water research (#3) 2 3 3 3 5 2 3 4 3 5 N and

L N N N N Explore approaches to integrate QMRA (and/or dynamic modeling) to better understand recreational risk, especially situations with rare, severe outcomes (#3) 4 2 4 3 4 4 2 4 3 4 N and

L L N N N Conduct future epidemiological studies in tropical and subtropical bathing waters (#4) 4 4 2 5 5 4 4 2 5 5 N N N L L Ensure that future epidemiological studies obtain data on and existing studies are reviewed for risk to children (#5) 5 4 5 5 5 5 4 5 5 5 N N N L N Review prior epidemiological studies to determine the risk of severe disease to pregnant women and their fetuses (#6) 2 2 1 3 5 2 2 2 5 4 L L L L L Review prior epidemiological studies to determine the risk of severe disease to the elderly (#6) 1 2 1 3 5 1 2 2 5 4 L L L L L

Review evidence about whether or not immunosuppressed individuals are at increased risk from recreational bathing waters (#6) 4 3 1 4 5 4 3 2 5 3 L N N N N

Determine how risks in tourists and visitors differ from those in residents (#7) 4 5 2 4 4 4 5 2 4 5 N N L N L Conduct studies on the role of bather shedding on transmission of illness and microbial water quality indicators (#8) 5 5 5 4 5 5 5 5 5 5 N N N L NDetermine the ecology of swimmingrelated waterborne pathogens (#8) 3 4 3 5 3 3 4 3 5 5 L L L L L Determine how many illnesses are prevented by beach closures?(#9) 4 4 4 5 3 4 4 4 5 5 N and

L N N N 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)U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 104 References

Chorus, I; Bartram, J (eds). 1999. Toxic Cyanobacter ia in Water: A Guide to their Public Health Consequences, Monitoring and Management. Lo ndon: E & FN Spon and Geneva, Switzerland: World Health Organization (WHO). Available at: http://www.who.in t/water_sanitation_hea lth/resourcesquality/t oxcyanobacteria.pdf.

Fleisher, JM; Kay, D; Salmon, RL; Jones, F; Wyer, MD; Godfree, AF. 1996. Marine waters contaminated with domestic sewage: Nonenteric illn esses 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 wa ter, and liver cancer in Florida. Harmful Algae 1(2):

157-168.

Payment, PR; Hunter, PR. 2001. Endemic and epidem ic infectious intest inal 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 Manageme nt 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 105 

## C HAPTER 

## 6

M ODELING 

## A PPLICATIONS FOR 

## C RITERIA AND 

## I MPLEMENTATION

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[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 107 6.1 Introduction

The Modeling workgroup was charged with determin ing how models might be incorporated into

future recreational water criter ia development and implementation. Workgroup members did not explicitly consider total maxi mum daily loads (TMDLs) in the discussion because models are already being used in TMDLs for pathogens throughout the Unit ed States. The discussion focused on what was generally felt to be the most important novel applications of models in new

or revised recreational ambi ent water quality criteria.

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

There is limited understanding regarding the sour ces 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 implemen tation 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 understandi ng of processes and mechanisms are more realistic for criteria development and impl ementation within the next 5 years. This is not to say that substantial re search should not go in to refining understanding of sources, fate, and transport of pathogens and pathoge n indicators and their spatial a nd temporal variab ility 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 genera tion”) recreational water quality criteria (see Section 6.5).

Workgroup members saw two roles for models in the development and implementation of nearterm (five years) new or revised criteria: (1) recreational water quality notification models and (2) models to support sanitary investigations (h ereafter referred to as “sanitary investigation models” for simplicity). Recreational water qualit y notification models are already in use in the Great Lakes and have proven to be effective a nd popular with the public (Francy and Lis, 2007; Olyphant, 2004; Whitman, 2007). Ther e are a handful of sanitary in vestigation tools and models

that are accessible to recreational wate r managers throughout the country (e.g., DigitalWatershed, the BASINS3 system). The ma in focus of this chapter is water quality notification models because these are easily a ccessible to a wide rang e of recreational water managers in the near-term. However, b ecause workgroup members viewed the sanitary investigation model as an area of near-term research activities and investigation, with possible applications in the ne ar-term development of new or revi sed criteria and/or implementation, discussion of sanitary investiga tion 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 l onger 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 result s from analysis of a water sa mple are available and a waterU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 108 quality notification is issued, the microbial water quality may have changed. This is due to the inherent variability in indicator bacteria levels ov er timescales shorter than a day (see Figures 4a and 4b), as measured by culture-based assay, both with selective membra ne-filtration media and

350

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50Enterococci (MPN/100 mL)

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 samp le exceedance.) SOURCE: A.B. Boehm, unpublished data (ENTEROLERT assay).

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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 109 defined substrate technologies such as Qu anti-Tray (IDEXX, Westbrook, Maine). Note, variability in indicator levels as measured by nucleic acid-based a ssays (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 pr otect 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 furt her information) the following:

1. Day-to-day water quality notifications s hould not be issued using a single sample standard in conjunction with a microbial assa y 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 im prove water quality notification accuracy.

2. Immediate research needs include the following:

a. Testing whether models can be used to predict health outcom es during upcoming epidemiological studies in California and in Alabama and Rhode Island and retrospectively for the Great Lake epid emiology study in the Great Lakes (Wade et al., 2006) (that is, risk = f[tem perature, tides, waves, etc.]);

b. Developing and testing simple notification models on different recreational water types with a wide range of s ources 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 pa ckage for developing local models.

6.1.2 Sanitary Investigation

Quantitatively determining the potential for a water body to be impaired with human pathogens is essential if the European Union (EU; EP/C EU, 2006) or World Health Organization (WHO, 2003) approach to criteria devel opment is undertaken (i.e., sanita ry 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 us ed to learn about the factors that influence water quality in recreation waters; for exampl e, high rainfall and wave action from a given direction and of a given height might lead to greatest impair ment. The occurrence of these environmental conditions can be used to trigger sampling for “toolbox” approaches such as analyses for human-specific or bird-specific mark ers and human pathogens to “rule in” or “rule out” high probability of human pathogen presence . In the second case (sanitary investigation models), simple, quantitative sa nitary investigation models that relate watershed attributes to probability of human pathogen im pairment may be developed.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 110 Summary near-term research needs (i.e., the next 2 to 3 years) specific to sanitary investigation models include (see Section 6.5 for furthe r 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, clim ate, soil moisture) can be used to determine the susceptibility of a wate rbody to pathogen impairment.

2. Research should be conducted to better understand how watershed activities and attributes relate to pathogen presence in st reams and receiving waters and include the following:

a. factors that modulate septic tank impact on waterbodies;

b. factors that modulate contri butions of animal wastes to pathogen and pathogen loads to waterbodies;

c. sources in urban landscapes (e.g., broke n/leaky sewer pipes, combined sewer overflows [CSOs], runoff); and

d. effect of meterological factors (e.g., rainfall, ev apotranspiration, etc.) on nonpoint 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 water body prior to impairme nt may be viewed as proactive rather than reactive. Such mo dels in use include deterministic models like Hydrological Simulation Program-Fortran (H SPF) and Storm Water Management Model (SWMM) for watershed loading, and CE-QUAL m odels for pathogen fate and transport (US EPA, 2002). Feedback from some environmenta l engineers and consu ltants who apply these models to pathogen and fecal indicator tran sport suggests they provide highly uncertain predictions for pathogen and indicator concen trations 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 t ype of sources), then models th at 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 recr eational water managers—especially if the EU or WHO approach to criteria development is u ndertaken. The relations hip between land use patterns and microbial water qua lity has been investigated qua ntitatively along the California coast (Handler et al., 2006), la kes of South Carolina (Siewick i 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 attr ibutes and pathogens a nd pathogen indicatorsU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 111 has been applied to numerous catchments usin g what is termed “pathogen catchment budgets (PCBs)” (Ferguson and Croke, 2005; Ferguson et al., 2007). A sanita ry investigation model, for example, might indicate that a completely unde veloped 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 si milar 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 phys ical parameters. The models are developed by assessing and exploring data for parameters that co rrelate most strongly with variations in water quality detected over the course of monitoring for pathogen indica tors. Promising variables are selected, regression models are tested, and the models are refined on th e basis of the results obtained using single variables an d/or sets of variables.

Another type of “model” for water quality notif ication is the Heal the Bay Beach Report Card grading system (http://www.healthebay.org/brc/stat emap.asp), which provides grades for water quality that are updated daily and formulated usi ng more than one water quality measurement. Given the major uncertainty and va riability 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 Modeli ng workgroup) suggested that neural network models be used to model water quality for notif ication. Neural networ ks relate independent variables to a dependent variable non-linearly and have been used to model fecal coliforms in some waterbodies (Kumar and Jain, 2006; Neel akantan et al., 2002). However, the Modeling workgroup members agreed that neural network m odels would not be accessi ble 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 th e near-term. They are, however, worth examining in the future.

Simple statistical models have been develope d for Great Lakes and West Coast recreational

waters that link fecal indicator concentrat ion with meteorological and water quality data/information, and include the following:

• water quality and dynamic hydrologic variable s (e.g., water temperature, turbidity, currents, wave height, tide le vel or range, lake height);

• optical property data (e.g., UV and visible irradiance, li ght scattering, cloud cover);

• meteorological parameters (air temperature, wind speed/direction, rainfa ll, pressure); andU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 112 • other factors (e.g., bird count s near a recreational water, number of swimmers in the water, video counts of swimmers and wildli fe, 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 indicato r concentrations vary depending on the type of setting of the recreational water. Among the desc riptive variables assessed to da te, turbidity, rainfall, tides, and wave height have been found to be among th e most highly-correlated. The success of these models has been evaluated by their effectivene ss 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/w aterquality/) for Lake Michigan and nowcasting models for Lake Erie are being used to warn th e public about potentially unh ealthy 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 th e Burns Ditch outfall (Ogde n Dunes, West, Wells Street, Lake Street, and Mar quette Beaches). These beaches are directly affected by contaminants in the Burns Ditch outfall, part icularly during prevaili ng 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 gene rated for the five beaches simultaneously. Similar applications are being developed for ot her 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 pi lot Nowcast project to test the use of a statistical model at Huntington B each, Bay Village, Ohio (Francy and Lis, 2007).

Nowcast was used as a tool for r ecreational water closure decisions for the first time in Ohio in 2006. If the testing goes well, the Nowcast model wi ll 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 th at is being continued as required by the National Beach Guidance and Required Perf ormance Criteria for Grants (US EPA, 2002). In Lake County Illinois (SwimCast) all r ecreational 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) recreati onal waters are monitored once a week. In Ohio (Nowcast) monitoring occurs 4 days per w eek at most Lake Erie recrea tional waters; and at Huntington Beach, monitoring was increased to 7 days per w eek during 2006 to provide a large data set to test the accuracy of the Nowcast system.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 113 Hou et al. (2006) and Frick and Ge (submitted) ha ve taken other important steps in developing

useful statistical tools for use in recreational wa ter 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 cha nge 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 co mmunication media and in a variet y of information formats. Internet postings, radio spots, and local signs have all been employed in communicating the output of regression model-based advisories. Model out puts intrinsically include an estimate of error. This is expressed in the Nowcast prog ram in a manner similar to the familiar weather forecast probability of precipitation (POP). Th at 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 pr ovided with the average prediction and the upper

and lower bounds of the 99 th percent confidence limit of the proj ected 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 c onfidence 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 current ly posted with a water quality advisory. The second tier is to provide additi onal information for those who desire to be more informed and could include posting the measured water qualit y, environmental water quality data, and the resultant numerical prediction on a website. The th ird tier is to provide detailed information on the Nowcast system and explain how statistical m odels are developed and tested, which can also be provided on a website or summar ized in fact sheets distributed to the public at the recreational water. A tiered system allows the recreational wa ter user the ability to choose their desired level

of information.

Effective communication to the recreational wate r 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 accepta nce. Because the Nowcast system is different from conventional water quality notification syst ems already in place (i.e., using the previous day’s measured bacterial indicator concentrati on), local officials may be apprehensive in accepting the new technological approach. Thus, demonstrating to local agencies that the Nowcast system provides a more accurate asse ssment of water quality conditions may be required before acceptance and implementation is achieved.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 114 6.3 Advantages and Disadvantages of Modeling

The main advantage of modeling for water quali ty 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 recr eational 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 invest igation model that relates land use activities and patterns to microbial water quality is that a mana ger may be able to rule in or rule out the presence of human pathogen sources in a watershed to relax criter ia, as is proposed in the EU (EP/CEU, 2006) and WHO (2003) appro aches to criteria development.

6.3.1 Advantages of Modeling

• Statistical/regression fecal indi cator estimation models are rela tively easy to create for an individual with knowledge of statistics and may in some cases only require one variable to adequately describe/predict the pathoge n indicator. Several government or private entities currently maintain hydro-meteorol ogical equipment and sensors (e.g., USGS, National Oceanic and Atmospheric Administra tion [NOAA]) with r eadily accessible realtime data via the Internet, which could be used at no cost to the recreational water quality manager if deemed appropriate for the specifi c recreational water. Collected descriptive variables can either be continuous or categor ical. 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 us e and watershed attributes may be readily available for incorporation into such a model (e.g., Digita l Watershed, see http://www.iwr.msu.edu/dw/).

• Water quality notification predictions may be made “near” real-tim e if required data elements (input variables) exist. This al leviates the delay curr ently experienced by culturable methods (18 to 24 hours for E. coli or at least 24 hours fo r enterococci). Even with the advent of rapid qPCR (molecular-bas ed) methods, there will continue to be time associated with collection, sample prepara tion, analysis, and results evaluation. For example, sample preparation adds an estim ated 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 cult ure- and non culture-bas ed methods currently have and potentially will continue to result in false negative (Type II) advisory/closure errors (e.g., contaminated recreational waters re main 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). Statis tical models created for variou s recreational waters in the Great Lakes have been successfully used to correctly advise/notify the recreational water

user of current feca l indicator conditions. Proper pub lic notification should result inU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 115 improved public health outcomes and is the ma jor benefit of statisti cal 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 co sts. 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 concentrati ons 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 reduci ng 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 progr amming), personnel costs should be reduced

over time.

• Many recreational waters are monitored in frequently due to ec onomic reasons or logistical issues (e.g., difficulty of sampli ng 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 wa ter operator (and other interested parties) with future assessments and sanitary investigation work. Simple linear relationships can help to identify potential sources of fecal in dicator 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 qual ity 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 prev ious studies have demonstrated that the currently-used bacterial indicators are statis tically associated with acute GI illness, predictions based on these pathogen indicato rs should be protectiv e of public health.

• Statistical models could possi bly be used to forecast poor conditions at recreational waters using forecasted descriptiv e variables available from NOAA.

• The statistical approach is flexible and coul d be applied to predic tion 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 allU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 116 required input data elements. Recreationa l water managers and operators (or other individuals) must be diligen t in ensuring that proper colle ction and data management techniques are used.

• Because current water quality notification m odels utilize statistical techniques, a relatively large (n = 75) and ri gorous data set is required to develop the model. Both dependent and assumed descri ptive variables should be co llected at least 3 to 4 days/week during the recreationa l 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 cond itions. 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, recreati onal water operators and managers, and the public may be apprehensive to accept the conc ept 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 pred ictions 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, ch anges in shoreline from extreme weather events, or new non-point sources of fecal contamination may reduce th e predictive ability of the model. If numerous under- or over-predic tions occur, additional data co llection activities would be

warranted to determine whether the model would need to be modified.

• Statistical water quality notification models appe ar to be most useful at recreational water locations that have occasional but infreque nt exceedances of curre nt bacterial water quality criteria. Recreational waters with consistently low or high fecal indicator concentrations may be very difficult to mode l. 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 m odels (e.g., bacterial fate and transport) or to provide load estimates fo r use in developing TMDLs.

• Current statistical water quality notificati on models are based on recreational water

criteria and thus meet BEACH Act a nd 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 ex isting model to incorporate the changed relationships of predictive variables to i ndicator concentrations. In addition, because fecal indicators are used to predict health ri sk, 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 geomet ric mean standard. Input from workshop participants revealed that these criteria are used differe ntly around the country with monitoring data. Output from water quality no tification models should be used with theU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 117 single sample standard and not the 30-day geom etric 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 an d 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 Implemen tation Realities workgr oup that recreational water advisories or closures instigated by model output would c ount against them for CWA §303(d) listings or other CWA applicat ions. Guidance for any new or revised

criteria that recommend models woul d need to address this concern.

• Models are site-specific and must be devel oped for various recreati onal 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 comple ted. In some cases, enough data may exist to analyze associations between the environmental va riables and indicator dens ities. For example, some states and local agencies collect data on air and water te mperature, rainfall, amount of algae wrack, and/or tide level dur ing compliance water monitoring. This type of ancillary data can be used to develop preliminary models and de termine if any relationships between indicators and readily available environmental variables exis t. This may guide additional monitoring needs

and variables to be assessed. As always should be the case, stri ct quality assura nce and quality control practices are to be followed to ensure th at a high quality data se t 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 locat ions and frequencies. This type of information can be obtained from recentl y conducted sanitary investigations, historical observations from local water resource managers, a nd/or visits to the recreational water site.

6.4.2 Model Development for Water Quality Notification

Statistical models have relative ly easy to obtain data needs. Data collection should include observations that cover the range of hydrometerol ogical conditions that are expected to impact the recreational water. Sampling should be conduc ted, at the very least, by collecting at least

two recreational seasons of data . A minimum of one recreationa l season will be necessary for model creation, while the second is used to gath er additional data and for model evaluation.

Water should be collected four or five times eac h week and the data set should contain a variety of sampling events to capture te mporal variability (morning a nd afternoon) under both wet and dry weather conditions. It is also necessary to attempt to sample and collect the full range ofU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 118 fecal indicator concentrations for a specific recreational water to en sure accurate future predictions. If current monitoring is conduc ted 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. Generall y, a relatively large (n = 75) and rigorous data set is required to develop a wa ter quality notification model. Recreational locations that have consistent good or bad wa ter quality are not good candidates for statistical models. Rather, sites with mixe d water quality conditions are the best candidates for statistical models. A representative sample of the wate rbody (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 us e of an EPA-recommended method.

The descriptive variables for each recreational wa terbody 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 automa ted processes, greater reliability of measurements, a nd reductions in personnel time.

Water quality notification models use a variety of descriptive variables and all are based on statistical correlations between descriptive variab les and indicator organism s. Wave height has been shown to have a positive association with fecal indicator bacteria at some beaches and thus is often included as an independe nt variable in water quality no tification models. Wave height can be estimated visually, measured with a gradua ted rod, or with pressure transducers. Wave height estimates can also be ob tained from an off-site extern al source, such as a NOAA buoy. Turbidity has also been proven to be a useful fa ctor for use in predictive models. Turbidity can

be measured with a field turbidimeter or in situ by use of a turbidity sens or. Models of marine recreational water sites may also include tides (Boehm and Weis berg, 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 f ecal indicator bacteria are sensit ive to sunlight (Boehm et al., 2002). Insolation can be measured using a pyranom eter on site or provided by external sources (such as NOAA). Rainfall, as well as wind spee d and direction, have been included in predictive

models. These data can be meas ured in situ using a weather st ation or obtained from a reliable source such as operating meteorol ogical stations, which are ofte n located at airports (NOAA, 2007). Streamflow rates from nearby tributarie s (USGS, 2007) and effluent discharge rate information from wastewater treatment plants ma y also be useful factors for inclusion in a predictive model. The number of birds at the r ecreational 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 bi ological wrack or algal mats as model inputs. Overall, the

factors/variables included in a mo del will be site-specific. A thorough review of factors that might be included in a water qual ity 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 a nd obvious output is the predicted microbial concentration and its associ ated confidence limits. A second output variable is the probability of exceeding an appropriate ta rget value; for example, the probability of exceeding the single sample maximum recreationa l water quality criteria (Francy and Darner, 2006). Either output may be used to issue adviso ries or closings of a recreational water site.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 119 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 need s are based on characteristics that are important to models used for TMDL implementation. A waterbody manage r would need data on land use within a watershed, types and numbers of domesticated and wild animals, publicly (and pr ivately) 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 mode l could generate a quantitative score of “very likely” to “not probable at all” regarding the possibility of having hum an 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, th e assumption is that an indicator monitoring program is already in place fo r the recreational water and computer hardware and statistical software are available. The following are 3 exam ples of costs for statistical modeling programs for 2 recreational seasons (60 obser vations 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 turb idity, 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 fo r measurements of wave heights, turbidity, wind direction and speed, and rainfall amounts. Expenditure s 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 calibrati on of equipment and 80 hours), and data compilation and model development (200 hours).

6.4.5 Understanding the Uncertainty and Measu ring 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 define d as the process used to generate information to determine whether a model and its analytical re sults are of sufficient quality to serve as the basis for decision making (CREM, 2003). Once a sta tistical model is constructed, it is important

to describe its usefulness or su ccess. A regression model is bui lt using a “training” data set comprised of dependent and independent variab les (Boehm et al., 2007). The ability of the model to predict the dependent va riable using independent descrip tive variable inputs within the training data set can be described by a root m ean square error (RMSE). A coefficient of determination (R 2 ) can also be used and is interpreted as the percent of th e variation of theU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 120 independent data set described by the model. Ho wever, the workgroup members agreed that this was not the best metric for evaluating model pe rformance. A third metric for testing the performance of a model is to ex amine the number of Type I and Ty pe II errors that result. Assuming the null hypothesis is that a recreationa l 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 positiv e), 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 nega tive). These two types of erro rs 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 qu ality 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 an alytical 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 independe nt and dependent variables not used to train the model is available. The success of a model during evaluati on 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 al so calculated. The model’s performance is then compared with the current method for assess ing recreational water quality (i.e., using the previous day’s measured bacteria l indicator concentration).

At a Lake Michigan recreational waterbody during 2004 (Olyphant, 2004; Pfister, 2007), swimmers were exposed to a health threat withou t 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, pr edictions derived from the model can never be completely accurate and the model can never co rrespond exactly to reality (CREM, 2003). After model validation (e.g., those that have been show n to correspond to field data), an additional year of data can be added to the model develo pment 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 activitie s, 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. ThereU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 121 were differences of opinion among workgroup members about how important TMDL model development is for the long-term for cr iteria development and implementation.

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

There is an immediate need to c onduct 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, a nd readily accessible to most recreational water quality managers (see Chapter 7). Statistica l 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 La kes recreational beaches (Francy and Darner, 2006; Francy et al., 2003; Frick et al., 2005; Olypha nt, 2005; Whitman and Ne vers, 2004; Whitman et al., 2006) and marine coastal beac hes (Hou et al., 2006). Although th ese 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 s hould not be issued using a single sample standard in conjunction with a microbial assa y 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 outcom es during upcoming epidemiology studies at Doheny Beach (C alifornia) and in Alabama and Rhode Island, and as well as the already comp leted 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 s ources 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 portab le 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 mode ls to health effects. One approach would be to concurrently conduct modeling studies along with planned epidem iological 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 theU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 122 epidemiological studies (e.g., tu rbidity, irradiance, wind speed/d irection, wave height, tides, temperature).

Another approach would be to retrospectively develop statisti cal models for sites of past epidemiological studies in the Great Lakes, wh ere appropriate data relevant to statistical modeling have already been colle cted (or can be obtained from existing meteorological data). For example, statistical models have been de veloped 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, rese arch is needed in recreational waters that are impacted by different sources of biological contaminants (non-poi nt or point sources such as POTWs) and that are described by a wide range of meteorological and wate r quality variables. Waters that are significantly impacted by PO TWs or non-point agricultural sources will be accorded the highest priority in site selection be cause past studies have shown that these sources are most likely to adversely affect human health . Sites located in th e 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 regr ession 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 peri odically with data ge nerated within a limited recent period—usually on the order of 30 to 60 days. Using the dynamic modeling approach, the predictions of bacterial concen trations have been signific antly 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 multiyear data from the period surrounding the date of interest. Additional re search 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 tw o activities (i.e., linking statisti cal models to health effects and developing statistical models for diffe rent types of recreational waters).

4. Communicating and traini ng modeling techniques. Various activities can improve the communication of modeling techniques and results to the public and training recreational water managers, including the following:U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 123 • creating a user-friendly portable p ackage for developi ng local models;

• training for running statistical models for recreational water managers; and

• including recreational water ma nagers on the decision process and polling them regarding their perception of its usefulness/feasibility.

Training is an important component towards accep tance and implementation of statistical models by recreational water managers a nd public health agencies. In a November 2003 workshop held as part of the Great Lakes Beach Association Annual Confer ence in Green Bay, Wisconsin, recreational water managers expressed as a high priority the need for informed training on

statistical models and other recr eational water monitoring activities. Similarly, training is being provided by EPA Region 5 on statis tical 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 re gionally, within a large waterbody, for example, should be explored.

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

1. Simple, heuristic, statistical /conceptual models that corr elate watershed activities (e.g., presence of treatment plant effluents, agricu ltural activities, domesticated animals) and attributes (e.g., slope, soil type, climate, so il moisture) can be us ed 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 pathoge n 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 contri butions of animal wastes to pathogen and pathogen loads to waterbodies ( high priority [5/5] );

c. sources in urban landscapes such as broke n/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 devel op an excellent model that would allow prediction of fecal indica tors or human pathogens. Additionally, important sources, and fate and transport processes will need to be el ucidated. These research needs will require a longer time horizon for completion and are summarized below.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 124 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 th e development of data and descriptors of processes that are required in deterministic models that predict fate and transport effects on pathogen concentrations in recreational wate rs. 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, z ooplankton 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 processe s, a better understanding of mobilization of pathogens and pathogen indica tors from sources within a watershed (i.e., from animal feces) and source strengt h 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

Water Column

Sediment Transport Transport Predation

Growth

Resuspension Sorption

Desorption Inactivation

Sedimentation

Predation Growth Inactivation

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).U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 125 is one example of a GIS-based software th at 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 fo r statistical models th at would be used for water quality notification and san itary 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 for ecasted variables (such as wind speed and direction, precipitation, wave height, and turbidit y, 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 don e if resources permit).

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June 2007 127 Kim, KH; Grant, SB. 2004. Public mis-notifica tion of coastal water quality: A probabilistic evaluation of posting errors at Huntington Beach, California. Environmental Science and Technology 38: 2497-2504.

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June 2007 128 Vereen, E, Jr.; Lowrance, RR; Cole, DJ ; Lipp, EK. 2007. Distribu tion and ecology of campylobacters in coastal plain streams (Georgia, United States of America). Applied and Environmental Microbiology 73: 1395-1403.

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distribution of Escherichia coli along southern Lake Michig an: An integrated approach. Applied and Environmental Microbiology 72(11): 7301-7310.

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June 2007 129 

## C HAPTER 

## 7

I MPLEMENTATION 

## R EALITIES

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 Ca re Agency, Santa Ana,

California

Charles Noss , USEPA James Pendergast , USEPA

Michael Tate , Kansas Department of Health and Environment[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 131 EPA requests that experts consider implementation realities when providing input to all specific and general questions th roughout this document.

The Implementation Realities workgroup members were charged with pr oviding input to EPA and the experts participating on the other six work groups concerning the practical implications of incorporating any proposed changes to the recreational bacteria criteria into State Water Quality Standards (WQS) and subsequent impacts on existin g water quality management programs. To this end, the workgroup members met frequently with and actively pa rticipated in the deliberations of the other workgroups over the course of the workshop. Implementation issues and concerns are therefore incorporated into th e individual workgroup ch apters throughout these proceedings. This chapter provides a summary of the major areas of concern identified by the Implementation Realities workgroup during the de liberations resulting from the workgroup’s

internal discussions as well as discussi ons with other workshop participants.

At the most basic level, the success of impl ementing any new initiativ e depends on providing resources and guidance that are adequate to accomplish the stated objectives. Where additional effort is needed, either additional resources mu st be obtained or existing resources must be diverted from other activities. Workgroup member s attempted to evaluate resource needs as a critical component of implementing new bact eria criteria across a broad spectrum of programmatic responsibilities from conducting necessary research to educating stakeholders and gaining acceptance of the public and regulated en tities of program changes, to actual impact on the day-to-day implementation of wa ter quality management programs.

The results of the discussions are presented in thr ee sections. First, an evaluation of the four principal program areas where recreational bacteria criteria are currently employed: (1) water quality beach notification and a dvisory 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 revise d recreational water quality criteria. The third and final section identifies the specific areas of research that workgroup members considered to

be most critical to facilita ting implementation efforts.

7.1 Application to Specific Program Areas

7.1.1 Beach Monitoring and Water Qu ality Notification Programs

The objective of this program is to provide accurate and timely info rmation to the public regarding the health risks associat ed with participating in recrea tional activities at marine and freshwater beaches. Significant concerns ha ve been expressed regarding both the accuracy and timeliness of the information currently provided.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 132 The most pressing need for regulatory authorities who conduct beach monitoring programs is to get better information to the public as quickly as possible regardi ng the safety of the recreational water. There is currently a minimum 24 hour de lay between the time when a water sample is collected, tested, and when the re sults 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 th e development of molecular-based tests that can provide results in just a few hour s following the initiation of the test compared to 24 hours for the currently used culture-based tests.

Rapid tests have several benefits. They shorte n the time from when an unsafe water condition occurs (an “exceedance”) to when the test reveals the existence of an exc eedance. 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 peri od thereby reduces the public he alth risk. The shorter test period also shortens the time it would take to re move 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 sour ce identification efforts such as in identifying a problem in a specific location by enabling more samples to be analyzed in a s horter 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 huma n 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-t ime” tests, they are not in fact real-time tests as there is still a delay of seve ral hours between water sampling an d 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 cult ure-based methods used to measur e indicator organism levels. The rapid tests will not shorten th e 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 appr opriate 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, sin ce 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 resour ces for increased monitoring.

Before any new test can be used broadly, the EP A will have to adopt and validate a standardized

method for its use. State and lo cal public health officials use th e results of monitoring to makeU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 133 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 rou tine use, issues related to test equipment, training, laboratory capacity, and certificatio n of laboratories will need to be resolved. The initial capital cost and any ongoing operation and maintenance cost s need to be calcula ted and compared to that of the currently used tests. Regardless of how “good” the mo re rapid tests are, if they are too expensive, regulatory authorities may not be able to afford them.

In addition, because the test endpoints of molecu lar-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 require d to gain “acceptance” of the

new indicator.

In general, any change in current monitoring pr actices (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 recreat ional waters are typically controlled to a large extent by a variety of meteorologi cal and water quality factors. Data for many of these factors (e.g., wind, rainfall, etc.) can be obtained in real or near-r eal time. By monitoring and identifying which of these factor s control indicator count change s, it is possible to create “predictive models” (see Chapter 6). Such mode ls are essentially mathematical equations that have the “controlling” meteorol ogical and/or water quality parameters as components. A

“robust” model that is validate d by comparison of predicted in dicator 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 mo dels may also reduce the need for rapid testing. Furthermore, they can be employed daily, prov iding information beyond that available from periodic microbial monitoring. However, it is im portant to note that predictive models are not

themselves criteria. Predictive models are tool s 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 de velop a predictive model within a stated confidence level may be significa nt. In general, model development may requireU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 134 significant time and resources depending primarily on the availability of data on indicator densities and associated predic tive 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 us able at other beaches or locations because the effect of a predictive variable such as wind dire ction on indicator densitie s 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 ex ample, limited funds may have to be used for higher priority task s such as improving impaired waters (e.g., fecal source identification).

Any proposed use of modeling results for co mpliance purposes is likely to present implementation difficulties. Model results may not be always accepted as “proof” of a water quality standards violation becaus e of the inherent uncer tainty associated with model results. That is, regulators are likely to require actua l 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 ofte n perceive monitoring as accurate and modeling

as estimates.

Statistical models are currently used in some St ates 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 corre sponding model would have to be modified, which would require additional resources.

It is important to note that modeling should not supplant routin e water quality monitoring, which will always be needed to detect unanticipated ev ents such as a sewer line break. Thus, regular monitoring provides an ongoing, dire ct measure of microbial wate r quality. Monitoring also provides data to help improve th e precision of m odel predictions.

General Considerations

Workgroup members felt that any new or revised recr eational 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 qua lity 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. Ne w or revised criteria must be expressed in a way that the authorities using the criteria are able to fully explai n the criteria and their health risk basis, in a readily understandable way to the public.

New or revised criteria should ha ve some “flexibility”; for exam ple, 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 cons istency so that the public has confidence that their health is being protected.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 135 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 demonstr ated 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 implem enting authorities will ne ed assurance that the

new criteria will be effective in ensu ring that public health goals are met.

Finally, the successful implementati on 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 Unite d States achieve the statutory requi red 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 tec hnology-based or water quality-base d limits on discharge quality and mandating discharge monitoring at a frequency ade quate to insure compliance with permit limits

and conditions.

Tiered Approach

Water quality criteria might be expr essed in a tiered approach; that is, that the criteria include multiple attributes, each of which apply for a sp ecific 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 n ecessitate choice of a pathogen indicator that achieves NPDES needs (see more below).

In addition, NPDES effluent limits are develo ped 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 ex posure condition that represents the upper 99 th
percentile of conditions (e.g., cond itions 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 im portant for deriving permit limits for pathogen

indicators in wet weather conditi ons because the flow conditions at the time of discharge can be extreme and represent rare ly occurring situations.

Pathogen Indicators

Changes in pathogen indicator s 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 re flect the efficacy of wastewater (sewage) treatment practices (disinfe ction). At a minimum, the indicator used forU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 136 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 th ere will be a need for differe nt indicators for ensuring the discharge achieves water quality st andards 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 concer n is based on research that shows the qPCR (quantitative polymerase chain reaction) signal do es not decrease post-chlorination. Many State public health codes require disinfection of hu man 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 implem entation that the analytical met hods be tested in a wastewater matrix and approved for use in wastewater. NPDE S regulations require th at 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 th e 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 di schargers may not be sufficient to conduct analyses for new pathogen indicators (e.g., molecula r-based methods). The start up cost of purchasing equipment for conducting the new analyses an d additional training for staff pos es a resource drain for both the dischargers and the regulatory authority that must provide oversight. S hould the dischargers

choose to contract out their laborat ory 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. Therefor e, States will need to amend their laboratory certification program to include th e new pathogen indicators. Th is 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 acc ounting 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 qua lity of the Nation’s water resources.

Assessment and listing based on the current am bient water quality criteria (AWQC) have disproportionately focused State resources on what are often perceived as minimal to non-U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 137 existent public health issues. States have expressed frustrati on at being effectively handcuffed by strict application of the criteria and the inab ility 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 indica tor levels are not due to human sources of fecal contamination and hydrologic fact ors that preclude recreational exposure, such as during or immediately after high rainfall events. Areas wh ere improvements can be made in the new or revised criteria and implementa tion guidance associated with the criteria includes monitoring, criteria, guidance, and (inland) flowing waters.

Monitoring

Workgroup members felt that new or revised recr eational 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 ma y, 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 nonattainment for assessment purposes. In a similar vein, if the beach advisory regulations are more stringent than State WQS, the advisory in an d 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—i n particular indicators of hu man 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 addre ssing and discounting pathogen

and indicator data not associated with an thropogenic 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, bimonthly, or annual basis and compare these data to previously collected data to assess trends. The problem will be exacerbated for assessment purpos es if new or revised criteria are adopted. It could take years to develop a st atistically significant data set.

If the format of the new or revised criteria requi res 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). Cr iteria that allow assessment samples collected at any frequency to be statistically manipulated to the appropriate exposure frequency w ould allow States to maintain their current monitoring approaches while appropriately applying the criteria.

Also, for ease of State implementa tion, new or revised criteria need to allow for some reasonable excursion frequency. Criteria expr essed as a percentile value (e.g., cannot ex ceed 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 tw o samples and would facilitate implementation for assessment

purposes.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 138 If the European Union (EU; EP/CEU, 2006) or World Health Organization (WHO, 2003) approach for criteria development is followed, ther e needs to be a clear distinction between the criteria that is needed to protect human heal th 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” m eets 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 rapi d 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 eff ect on the overall assessment process that is

conducted on data collected over a 2 year period.

Workgroup members expressed concerns with esta blishing a new or revi sed 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 modi fy the criteria and allow for nonhuman sources of fecal contamination, the frequency of performing th at investigation would need to be identified in assessment guidance. There was a strong preference among workgr oup members that the frequency be longer than the tw o year assessment cycle for St ate’s issuance of assessment information pursuant to §303(d) an d §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 be tween previously used indicators and any new indicator(s) so informa tion from past monitoring is not lost. If a

“translator” is no t available, it might take several ye ars to build up e nough information to conduct a statistically valid asse ssment for pathogen indicators.

Guidance

If new criteria indicator/me thodology combinations are adopt ed, issuance of guidance for implementation will be imperative. With the lik elihood of rapid molecular-based test methods, sanitary investigations, and so on, guidance will n eed to accompany the criteria to help States understand how to apply the new or revised cr iteria 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, consider ation 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; orU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 139 • changes to the use/criteria wh en the use is not taking place (e.g., when recreation is unlikely to occur such as during winter m onths or during or immediately after heavy rainfall).

Lastly, an indicator applicable to flowing freshwat ers needs to be identified. As stated elsewhere in these proceedings, E. coli appears to be a more appropriat e freshwater indicator of fecal

contamination than enterococci. E. coli are a subset of fecal colifo rm bacteria while enterococci bacteria are a separate group of enteric bacteria. More recent wa ter 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 manage ment 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 w ith the current (US EPA, 1986) criteria are typically difficult to develop and explain to stakeholders because expressing pollutant loadings of bacteria or pathoge ns in terms of mass is nonsensi cal. 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 allo cations for non-point sources in mass units does not make sense to the vast majo rity of TMDL practioners and those responsible for implementing bacteria TMDLs. For this reason, alternative means of expressing loading reductions (e.g., “percent reducti on,” “load duration curve-base d,” “reference watershed” methods) have been used by many States. TMDL development for waters impaired by excessive indicator bacteria densities is further complicat ed in that the necessary load reductions are typically strongly linked to hydrologic factors a nd intermittent sources such as stormwater runoff. Establishing a static st eady-state design condition, as is frequently done for other types of pollutant impairments, is not possible for ba cteria due to the significant wet weather eventdriven characteristics of ma ny bacteria-impaired waters.

Workgroup members viewed criteria expressed in numerical terms as a pr actical necessity to implementing any revised recreational use criter ia in TMDL programs due to the need to quantify loadings. Implementation realities dictate that the criter ia be expressed in terms that facilitate calculation of an acceptable daily lo ading 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 expe rts expressed a diversit y 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 inte nse resistance from Sstates if future criteria guidance proposes criteria expressed as a “never to be exceeded” value.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 140 An acceptable exceedance frequency is critical to facilitate design of treatment requirements and best management practices (BMP s) 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 bacteria l densities in natural systems w ould 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 th e TMDL implementation requirements would be achieved much more readily if additional confid ence 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 “d iscount” the contribution of cert ain lower risk sources (e.g., nonanthropogenic) 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 inve stigation there should be guidance provided to encourage consistency in sani tary 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 s ource tracking, use of more human-specific indicators) may also be acceptable provided the co st 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 Workgro up 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 wa ter 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 potentia l 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 occurre nce 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 Appr oaches for Criteria Development

This section describes the implementation cons iderations for each of the three alternative approaches for the development of new or revise d recreational water quality criteria that were proposed and discussed at the workshop (see Chap ter 1). Some of the concerns regarding implementation that are common to all th ree approaches include the following:

• level of discriminatory power/sensitivity of a method;

• if rapid method is used, difficulty in implem entation in some place s (e.g., holding time);

andU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 141 • 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 conc erns described in the following sections, would be eliminated if the following statements were true:

• epidemiological studies demonstrate that i ndicator organisms are sufficiently correlated to human health risk;

• studies provide a scientific basis for disc ounting risk to human health from wildlife sources of fecal contamination;

• criteria included flexibility to account for th e reduced exposure (and thus, lower risk) of use at extreme conditions (e.g., high flow);

• relationships between advisori es and impairments were mo re clearly defined in EPA guidance;

• level of disinfection necessary to provide ad equate pathogen reduction/inactivation in human sewage was determined; and

• criteria applied for NPDES purposes includ ed flexibility to account for wet weather

conditions.

7.2.1 WHO Approach

The WHO approach provides a range of risk levels and accounts fo r differences in relative risk resulting from site-specific cons iderations of sources of indica tor organisms based on the results of a sanitary inspection performed prior to the a ssessment of monitoring results. The following implementation concerns are not specific to an y specific application of the WHO model, but rather reflect the genera l 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 essen tial to have available a reliable methodology to distinguish between human and natu ral 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 accepta ble. 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 determinin g 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 w ith their overall mission.

It is also important to be able to quantify th e risk from domestic animals and livestock and include this risk if a WHO-based approach is pursued. Although these sources of fecalU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 142 contamination are nonhuman in nature, these animal s live in close proximity to humans and may carry human (zoonotic) pathogens in their feces(e.g., E. coli O157:H7, Cryptosporidium parvum ; 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 expos ure 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 W HO 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 wa ters because exposure in these

two situations are different.

There are several implementation issues that ar ise if the WHO model is applied using a qPCR analytical method. The first issue is the capacit y of States and NPDES di schargers to adopt and use a qPCR method, as initially, there may be insufficient labor atory capacity to conduct the method. Specific concerns with respect to NP DES facilities are discussed in the preceding Section (7.12) on the NPDES permitting program. Additionally, it is reas onable 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 qP CR is its apparent inab ility to confirm that disinfection is being properly applied. As discussed previous ly, NPDES permits need to both assure that WQS are achieved a nd that State disinfection require ments are being met. If qPCR method is used to apply the WHO approach, then another indicator usin g 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 san itary investigation shoul d not be overly prescriptive to the point of making the investigation res ource-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 sa nitary investiga tions, then the public will perceive that the investigations ha ve 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 sa nitary investigations by the time the new or revised criteria are adop ted into their WQS.

The WHO approach includes columns that character ize different risk (see Table 1, Chapter 1).

Two of the columns include water characteriza tions 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 implie s 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 fu rther distinction between “good” and “very good” outcomes should be voluntary.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 143 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 envi ronmental agency, or at beaches where there are wildlife sources that pose risk. It is uncertai n how such a situation would work with the WHO model, and this would need to be developed.

The WHO model uses ranges of pat hogen densities. This allows Stat es to select which specific value to use, and thus result in inconsistencie s on thresholds to close or open beaches between various states. It is much more preferable for th e 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 de scribe the precision of epidemiological-based criteria applied to a wide range of waters coupled with the prec ision 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 singl e risk level but allows for adjustment of the assessment result based on a sanitary investigat ion performed following review of monitoring

results.

Like the WHO (2003) approach, the EU (EP/CE U, 2006) model uses sanitary inspections; however, unlike the WHO approach, the EU mode l uses the inspections to rationalize that monitoring results above the criter ia levels do not indicate an el evated risk to human health. Thus, the rigor of any type of sa nitary investigation that may be required for an approach based on the EU approach seems to be greater than fo r 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 sufficien t sanitary survey for many bathing waters (Paul Hunter, University of East A nglia, U.K., personal communication, 2007).

As was the case for the WHO mode l, 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 contaminati on. Specifically, States will need to know how good are the techniques to distinguish betw een risks from human and nonhuman sources, and what is the degree of risk from nonhuma n sources. Thus, the discussion of the WHO approach on these topics likewis e applies to the EU approach.

As one way to implement the EU model, EPA coul d 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 determini ng how to conduct the sanitary investigation/disc ounting process.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 144 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 characteri zes beaches using the 95 th 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 mode ling. 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 li mited data. If there is no m odel, 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 s hould be applied with only one “a cceptable risk” level. If there is more than one acceptable cate gory of good, it implies th ere 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 fu rther 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 sanita ry investigations or source identification.

The original basis for the (EPA) 1986 criteria were freshwater a nd marine water epidemiological

studies conducted at a limited numb er of sites with restricted geographic extent and waterbody type (lake beaches and marine beaches). Therefor e, 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 influe nce. 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 wa ters 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 characte rize the microbiological quality of the water. There is a variety of opinion as to the most appr opriate indicators for fresh and marine waters. However, there is evidence that E. coli is the most suitable indica tor for flowing freshwaters while enterococci, either by culture- or molecular-based met hods, 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 la ck of approvable test methods for wastewater effluent. If new indicator organisms or test me thods are identified for the new criteria, approved test methods must be developed for all potent ial needs such as NPDES permitting and ambient water quality monitoring.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 145 The 1986 criteria provide minimal implementation gui dance. 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 cau sed 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 fl ows and nonhuman sources of fecal contamination.

EPA needs to provide more scientific data an d information to States for implementation of pathogen indicator criteria. Stat es have concerns regarding the effectiveness of existing sewage treatment capabilities on new indicator orga nisms. In switching from enterococci or E. coli as an indicator, there is concern that disinfection designs may not me et permit limits based on the new

indicator criteria. This issue needs to be addr essed by EPA so that the State programs will have consistent, valid, and scientifically defensible re sponses when these concerns are raised during the implementation of new WQS.

7.2.4 Alternative Approaches

Two additional potential approaches to consid er in the development of new or revised recreational water quality crit eria 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 a llow for demonstration of mitigating (or discounting) factors to be comp leted by a fixed date after crit eria adoption. This has the advantage in preventing wate rs from being CWA §303(d)-liste d 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 mitigati ng factors prevented designated use attainment.

2. The largest implementation concern with the single value (EPA) 1986 criteria is regarding assessment. An alternative approach to de veloping new criteria could incorporate the existing 1986 criteria with the fo llowing 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 duri ng 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 suppor t 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. Opportuniti es to leverage the value of individual re search programs by employing data collection designs that may be useful to answer multiple questions should be exploited.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 146 7.3.1 Near-term (Next 1 to 3 Years)

Beach Monitoring

1. Provide a quantitative protocol to identi fy 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 othe r anthropogenic sources? The WHO and EU approaches to criteria development provide for “discounting” exceedances if it can be determined they are of nonhuman origin throu gh 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). A lthough the new or revised criteria would need to address all potential risk s, a delineation of the categories of risk made available to the public would improve water quality notif ication and informed consent aspects of implementation. Specifically, the perceived ri sk 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 or igin (e.g., cattle, poultry). The public may

wish to make an informed decision about us age relative to specifi c pathogens such as enterohemorrhagic E. coli (EHEC) that are potentially associated with agricultural land

usage.

3. Determine under what conditions a sanitary i nvestigation would be sufficient (as opposed to microbial source tracking). This resear ch is most important if the WHO and EU approaches are being considered.

4. Identify minimum elements that a sanitary i nvestigation should include. Again, the focus should be on the minimum elements necessary fo r a reliable sanitary investigation. If the requirements for a sanitary investigation ar e too onerous, they will become resourceprohibitive and of minimal value. Assess the reliability, accuracy, and validity (etc.) of the various types of sanitary investigatio ns. Without some sort of standardized investigation criteria, inconsistencies will re sult in the implementation of the criteria and create potential variances in hea lth 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 identific ation 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 culturebased 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 ha ve significant impacts on NPDES permit monitoring programs. Non cu lture-based methods may not ad equately assess treatment processes or determine permit compliance.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 147 2. Develop an improved understanding of disinf ection using the different indicators.

Determine how well each indicator is in meas uring 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 intermitte nt microbial pollution discharges, CSOs, urban runoff, and concentrated animal feeding operations (CAFOs).

4. Evaluate the effectiveness and cost of stor mwater and agricultural BMPs as related to pathogens and microbial contaminants. This evaluation should be made in concert with epidemiological studies/QMRA analyses that wi ll determine the risk from different types of sources (urban and agricultural runoff, i ndigenous 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 th at disinfection could eventually be promulgated as a mandatory tr eatment technology nation wide 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 determin e the risk from different type s 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 flowi ng 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 developm ent for inland U.S. waterways.

3. Need to better understand th e health-basis for allowa ble exceedance frequency. Additional explanation is need ed to justify percentile crite ria differences between WHO, EU, and EPA (1986) criteria develo pment approaches (e.g., use of 95 th or 90 th percentile).

4. Conduct research to better unde rstand how to measure the impact of regrowth and persistence in sediments of indicator bact eria on water quality. The source of some problems of high pathogen indicator levels may at times be due to re growth 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 vira l and protozoan por tion of effluent.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 148 Overall

• Develop methodologies that are pathogen-specific.

References

EP/CEU (European Parliament/C ouncil 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 Re pealing Directive 76/160/EEC. Official Journal of the European

Union L64: 31-51. Available at: http://europa.eu.int/eurlex/lex/LexUri Serv/site/en/oj/2006 /l_064/l_06420060304en00370051.pdf.

Strauch, D; Ballarini, G. 1994. Hygi enic 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-1 

## A PPENDIX 

## A: C HARGE TO THE 

## E XPERT 

## W ORKGROUP 

## M EMBERS

PURPOSE

The purpose of the Pellston-type 1 Experts Scientific Workshop on Critical Research and Science Needs for the Development of Recreational Wa ter Quality Criteria is for EPA to obtain individual input from members of the broad scientific and tec hnical community on the “critical path” research and science needs for developing scientifically de fensible new or revised Clean Water Act (CWA) §304(a) recreational wate r 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 “a dvisory water quality guidance on th e 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 protec t swimmers from illnesses associated with pathogenic microbes in coastal a nd Great Lakes waterbodies.

In adopting new or revised water quality standa rds, States must adopt criteria that are scientifically defensible and protective of the us e, but they have flexibility to do so by adopting EPA’s recommended criteria, adopti ng criteria to refl ect site-specific conditions, or adopting

other criteria that are scientif ically defensible. In the case of criteria EP A publishes under § 304(a)(9), States with coastal and Great Lakes waters are re quired to adopt EPA’s new or revised criteria for pathogens and pathogen i ndicators into State Water Quality Standards (WQS).

Once adopted into State WQS, water quality crite ria 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 polluti on with the goal of attainment of the criteria, including National Pollutant Discharge Elim ination System (NPDES) permits, water body assessments to determine use attainment, an d development of Total Maximum Daily Loads (TMDLs). In addition, these WQS used by St ates 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 techni cal 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 fr om 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 resp onsible 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-2 Historically, EPA’s recommended criteria for protect ing 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 colifor ms, as the primary contact recreational 3 criterion. In the late 1970s and early 1980s, EPA c onducted public health studies ev aluating several organisms as possible indicators, including fecal coliforms, E. coli , and enterococci. The studies showed that enterococci are a good pred ictor 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 – 1986 4 ) 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 (criteri a set as geometric means of 33/100 mL in freshwater and 35 cfu/100 mL in marine water). These recommendations re placed EPA’s previously recommended bacteria

criteria for fecal coliforms of 200 cfu/100 mL. EPA’s criteria recommenda tions 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 indi cate fecal contamination, and the assumption is that pathogens co-occur with incide nces of fecal contamination.

Since EPA issued its recreational criteria over 20 y ears ago, there have been significant scientific advances, particularly in the areas of molecular biology, microbi ology, and analytical chemistry.

EPA believes that these new scientific and techni cal advances need to be factored into the development of new or revised CWA §304(a) criter ia for recreation. To this end, EPA has been conducting research and assessing relevant scientific and techni cal information to provide the

scientific foundation for the deve lopment of new or revised crite ria. 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 cr iteria, specifically for

Great Lakes and coastal marine waters.

OVERALL CHARGE TO THE EXPERTS

Experts are asked to provide their individual knowle dge and insight that will help EPA define the critical path research and science needs, recogniz ing 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 fo cus 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 fu ture or “next generation” criteria, this is not the primary purpose of this Workshop.) “Next ge neration” 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 EP A publishes the initial criteria, and every 5 years thereafter.)

3 Primary contact recreation includes activities that coul d be expected to result in ingestion of water or immersion. These activities include swimming, water sk iing, 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-3 Although not the focus of this Workshop, EPA is aware of stakeholder concerns regarding implementation issues associated with the existi ng (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 encourag ed to identify aspects of the 1986 criteria which have been cited as problematic, and, to th e 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 scientif ically sound, protective of the designated use, implementable for broad CWA purposes, and wh en implemented, provide for improved public health protection. By scientif ically sound, EPA means that the criteria must be based on the science and peer reviewed studies available at th e time the criteria are de veloped. 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 br oad purposes for which CWA criteria are intended, including beach monitoring and water quality no tification 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, th e new or revised criteria, when implemented, should also provide for improved pub lic 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 provid ed by the experts and collected by the Chairs throughout the week’s

discussions. The Chairs will be asked to summar ize commonalities and differences in the input provided by participants, and li st out the projects and activitie s that the individual experts identified as critical to the development of ne w or revised CWA §304(a) cr iteria in the near-term, recognizing that research th at cannot be completed in 2 to 3 year s 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 expe rt views on the following topics: appropriate pathogens or pathogen indicators, along with av ailable and appropriate methods; single versus “toolbox” criteria approach; implementation issu es; 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. Afte r the workshop, EPA cont ractual 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 n ear-term criteria.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-4 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 cr iteria development and implementation. A threshold issue that impacts the deliberations of all groups is whet her EPA should consider a fundamental change in its approach to recommending recr eational criteria; for example, switch from a single criterion in all places to a diversified toolbox or tiered approach, using multip le criteria, or several tools supporting a single criterion, or some other combination.

Break-Out Group #1: Approaches to Criteria Development (See Chapter 1) 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 f actors, 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 not ification, and possibly other me thod-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 th e 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 gui de a robust discussion am ong the experts in this group. The results of this discussion will impr ove the understanding of the advantages and disadvantages of various appro aches to criteria development.

1. What approaches exist currently for setting limits of pollutant s that may be relevant for developing nationally recommended recreatio nal water quality cr iteria? Consider approaches used for other kinds of pollutants in water, in other environmental media, and by other countries as well as approaches be ing 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 n eeds that should be addressed in developing or selecting an appropriate approach? Can this research be completed in time to be used in criteria developmen t in the near-term?

5. Is a “toolbox” approach appropria te for developing new or r evised 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 th ese proceedings, chapter

numbers are referred to for easier reference.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-5 7. What are desired features or characteristics that w ould make a “toolbox” approach appropriate?

8. Would a “toolbox” approach achi eve 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 w ould achieve additional public health protection?

9. Criteria for secondary contact recreation co uld be part of a “toolbox.” What approaches would be appropriate for deve loping criteria for secondary contact recreation? Would this approach be different fr om 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 recr eation? Can this research be completed in time to be used in criteria developmen t in the near term?

11. What are the implementation considerati ons of the different approaches for CWA purposes (1) beach monitoring and notificat ion, (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., fie ld sampling issues, laboratory challenges, staff training, etc.)?

Geographical Applicability : Options for ensuring criteria are appropriate in a diverse range of

recreational waters include EP A recommending geographically di fferent approaches, numbers, or indicators, applicable to di fferent regions (e.g., fresh and mari ne waters, coastal and inland waters, tropical/subtropical and temperate wate rs) or types of waterbodies (e.g., lakes and flowing waters).

1. Is a single criterion ava ilable that is applicable for th e 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 n eeds in developing or selecting an approach that will appropriately factor-in diverse geographical conditions?

Expression of Criteria : EPA is currently assessing the de gree to which criteria should be expressed as the mean concentration over a peri od of time (e.g., 30 days) and/or as a daily or

instantaneous maximum value.

1. Given the diverse needs of the CWA program s and the overarching goal of protecting and restoring waters for swimming, what protec tion is provided by establishing a 30-day “average” value as the criteria? What additi onal protection (if any) is provided by a daily or instantaneous maximum value? Fr om a scientific standpoint, is one measure better scientifically than another for particular purposes (e.g., mean value for purposes of identifying impaired wate rs and daily maximum for beach monitoring and notification purposes)? Why?U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-6 2. What are pros and cons of expressing the criteria differently for the various CWA program needs?
3. What are the implica tions of instantaneous or daily valu es 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 il lnesses that could oc cur 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 cr itical 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 fo r (1) beach monitoring and notification, (2) development of NPDES permits, (3) assessmen ts to determine use attainment, and (4) development of TMDLs? Are there practical considerations that could preclude, or greatly limit, the usage in routine, regulat ory implementation (e.g., field sampling issues, laboratory challenges, staff training, etc.)?

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

Although EPA wants the experts to consider implem entation realities when providing input to all general and specific questions throughout this document, the fo llowing 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 im plementing the (EPA) 1986 criteria? What

worked well and not so well? How could we av oid repeating past “mis takes” that lead to delays in adoption or difficulties in implem enting these criteria?

3. Which approaches to criteria development have the most potential for success in implementation when new or revised crit eria are adopted into State water quality standards? Why?

4. What are general features or characterist ics that would make new or revised criteria easy to interpret and impl ement for states when adopted into State water quality standards? Why?

5. Would a “toolbox” approach be easier or more difficult to interp ret and implement?

What are desirable characteri stics of a “toolbox” criter ion 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)?U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-7 7. What are critical path resear ch and science needs that w ould enhance implementation of

new or revised criteria in the near-term?

Break-Out Group #3: Pathoge ns, 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 i ndex microorganisms and specific pathogens are

discussed below.

The following set of questions is intended to gui de a robust discussion among the experts toward

the identification of critical research and scienc e 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 St ate public health and

environmental labs or where methods will be rea dy for day-to-day use in these labs within the next 3 years.

A. Fecal matter indicators (as surrogates for gastrointes tinal 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 di sease? (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 impro ved protection against diseases (e.g.,

Bacteroides spp., Clostridium perfringens , coliphages or other phages)? Why?

3. Are there any chemical biomarker fecal in dicators (e.g., fecal stanols, detergents, whiteners, caffeine) that can be used to be tter protect public hea lth and meet all CWA purposes than the current indicato rs of fecal contamination?

4. What critical research would improve or wide n the selection of feca l 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 co uld be done to support this

7 A specific pathogen belonging to a broader group of pathogens which would serve as a surrogate for the presence and/or health ri sks 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).U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-8 approach? (also for skin, upper respiratory tract, ear, eye disease criteria considerations)

2. What are the advantages and dis advantages of this approach?

3. What might be the most appropriate pathogens or index organisms? Why?

4. What data support a dose-response relations hip between a particular pathogen or its

index in recreational wate r and any disease outcome?

5. The BEACH Act requires that EPA conduct re search 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 hum an 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 criter ia 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 potentia l to improve monitorin g, better express health risks from swimming exposures, and be more comp rehensive in their use to meet all criteria needs and provide more efficient and cost effective procedures.

C. Application of fecal indicators, pathogen in dex 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 th at would provide an acceptable criteria approach?

2. What specific combined applications woul d have merit in mee ting criteria needs?

3. Would the combined applications best utilize an analytical toolbox approach or a tiered analytical approach?

4. Would the criteria endpoint re flect a general gastrointestin al disease target or a dose response estimate base on more limited dise ase symptoms reflecting the metrics used?

5. What research is important to make the sel ection of combinations available for the new or revised criteria and the next generation criteria?

6. Can adoption of the WHO/A nnapolis Protocol approach 8 that combines sanitary reconnaissance survey inform ation along with microbial assessment to develop surrogates of fecal contamination (predic tive modeling) on the day to manage water advisories provide improved health gains o ver current criteria? Are there sufficient examples of this approach to develop new/im proved use of indica tors/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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-9 D. Applications of all the above for all categories of wa ters, 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) Temperate 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 D1?

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

The 1986 criteria are based on a cu lture 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 in clusion in new or revised criteria. EPA is interested in input on what other methods or to ols are available and should be considered for developing criteria/standards that would meet all CWA purposes.

The following set of questions is intended to gui de a robust discussion among the experts toward

the identification of critical research and scien ce needs in the development of detection methods

for the new criteria. It is essential that th is group focus discussions on those methods (and pathogens, pathogen indicators or indicators of fecal contaminatio n) that are ready now for dayto-day use in State public health and environmenta l labs or would be read y 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 organi sms that EPA should consider for water quality criteria development?

2. Are there data to support othe r 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 develope d in your view?
4. How important is time-to-results in met hod selection from the pe rspective of public health protection?
5. What further work needs to be done to ensure that the qPCR method or other promising (molecular) methods are consider ed 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., fo r beach monitoring and notification) how could other methods be “lin ked” to the qPCR me thod so that they are scientifically sound and easily implementable? If only qPCR has been va lidated through epidemiological studies to predict health effect s, what other studies could be done to link qPCR to other methods/indicators that ma y be more appropriate for §304(a) uses?U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-10 8. Depending on the method used, how could contam ination 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 lin ked to the necessary source to address the

contamination?
9. Current culture-dependent methods and qP CR 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 crite ria would culture me thods, including EPA Methods 1600 and 1603, be most suitable for and why?

11. What further work needs to be done to ensure th at 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 crit eria development in the nearterm?

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 surv eys) be developed to enhance the insight provided by water quality indicators?

14. What characteristics of analy tical methods are essential fo r 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 pe rmits, (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, regulator y implementation (e.g., field sampling issues, laboratory ch allenges, staff training, etc.)?

Break-Out Group #5: Comparing Risks (to Humans) from Differe nt 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 anim al waste. The followi ng 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 (sewage/wastewater) treatment work (POTW) protective, under-protective or overprotective of other poten tial sources of human pathoge n? Why or why not? Are there data to support this conclusion?

2. Based on the “state of the sc ience,” 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)?U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-11 3. To what extent is it reasonable to apply risk estimates from POTW-i nfluenced beaches to

non-POTW beaches? Do we understand scie ntifically 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 de finition of GI illness [i.e., no fever]; more sensitive molecular methods; assuming that POTW risks = non-human source risks, etc.)

5. How should EPA evaluate risk that may ha ve 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: Accepta ble 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) agai nst various types of waterborne diseases (GI and non-GI) caused by pathogens.

The following set of questions is intended to gui de a robust discussion among the experts toward

the identification of critical rese arch 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 underst and whether nationally recommende d criteria (based on the types of epidemiological studies EPA and others have conducted to date) provide protection against all types of major water borne diseases? If not, for which subgroups, pathogens, and waterborne illnesses is the scie nce lacking? What ty pes of studies would be needed to answer these types of questions about the degree of pub lic health protection provided by nationally recommended criteria?
2. What methodologies or approaches for asse ssing 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 associ ated with differing levels of fecal contamination as the foundation for d eveloping nationally recommended criteria?
4. Is there any scientifically- based reason to establish differen t “acceptable” risk levels for fresh water versus marine water?
5. Is the phrase “acceptable risk” from the (U S 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 protect ion provided by the im plementation 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 reallyU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-12 protecting people from more than GI illness (w ith fever)? What science is needed to understand what protection is provided by th e implementation of the 1986 criteria?

Protection of Humans from Drinking Wate r and Fish and Shel lfish 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 recreationa l 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 shell fish from the same water? Is the science sufficient to support a determi nation that recreational criteria will also protect drinking water uses and shellfish uses?

2. What additional science is ne eded to ensure that recreatio nal criteria protect people from illnesses associated with recreation and also protect people from illnesses caused by drinking contaminated recreational water or consum ing fish and shellfish found

in contaminated recreational water?

3. Is the science there now to understand and characterize th e degree of protectiveness for

all these elements?
4. If the science is not there, what are the cri tical path science or research needs to address

this?

Break-Out Group #7: Modeling App lications for Criteria Devel opment and Implementation (See Chapter 6)

Predictive modeling may be useful as a tool to help with th e development of site-specific recreational water quality criteria, and the implem entation of criteria. Presently, EPA is not considering models in its plans for new or revi sed criteria in the near -term. However, in recognition that some states and municipalitie s currently use models effectively in beach notification programs, EPA solicits input from e xperts regarding the potential use of models as tools to aide implementation of the new or revised crite ria, and further reque sts input on critical

research and science needs in this area for future criteria development.

1. What potential role could estimating te chniques (or models) play in criteria development? In the setti ng of site-specific criteria for recreational waters?
2. What potential role coul d estimating techniques (or m odels) play in implementing nationally recommended criteria for recreational waters?
3. What are advantages and disadvantages of us ing 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 regi mes to include or support modeling?
5. What is the “state of the science” in modeling to support recr eational water quality criteria development and implementation?U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 A-13 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 re presented and considered in ri sk analysis and public health

decisions?
8. Do differences in the nature of the resp ective uncertainties inherent in modeling versus monitoring require different means of addres sing 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 certa in “uses” of criteria (i.e., beach notification, assessment, permitting, TMDLs)? How would modeling be used together with monitoring to cover all “u ses” of criteria?
9. In models that are currently being used to predict levels of indicator bacteria, how are advisory/closure decisions being made usin g model results, and how are the results and/or the risk being communicated to the pub lic? 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 wate r 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?[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 B-1 

## A PPENDIX 

## B: P ARTICIPANT 

## L IST

Experts by Workgroup

Approaches to Criteria Development Implementation Realities Joel Hansel, Chair Lee Dunbar, Chair

Mark Gold Thomas Atherholt David Kay Bart Bibler John Ravenscroft Lawrence Honeybourne

William Robertson Charles Noss Jeffrey Soller James Pendergast David Whiting Michael Tate

Pathogens, Pathogen Indicators, and

Indicators of Fecal Contamination Methods Development Nicholas Ashbolt, Chair Stephen Weisberg, Chair Roger Fujioka Alfred Dufour Toni Glymph Charles Hagedorn

Charles McGee Sharon Kluender Stephen Schaub Erin Lipp Mark Sobsey Robin Oshiro Gary Toranzos

Comparing Risk (to Humans)

from Different Sources Acceptable Risk Dennis Juranek, Chair Paul Hunter, Chair

Rebecca Calderon Michael Beach Jack Colford Lora Fleming Elizabeth Doyle Peter Teunis Graham McBride Timothy Wade Samuel Myoda

Modeling Applications to Bacteria Criteria Development and Implementation Alexandria Boehm, Chair Donna Francy

Mark Pfister

John Wathen Richard ZeppU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 B-2 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 tom.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.fl.us

Alexandria Boehm (Chair) Stanford University, California

650-724-9128

aboehm@stanford.edu

Rebecca L. Calderon

USEPA

919-966-0617 calderon.rebecca@epa.gov

Jack Colford University of California, Berkeley

510-642-9370 jcolford@berkeley.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 Fujioka University of Hawaii, Manoa

808-956-3096 roger@hawaii.edu

Mark Gold Heal the Bay, Santa Monica, California

310-451-1500 mgold@HealTheBay.org

Toni Glymph Wisconsin Department of Natural Resources

608-264-8954 Toni.Glymph@Wisconsin.govU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 B-3 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 1570 423565

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.john@epa.govU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 B-4 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 Soller Soller Environmental, Berkeley, California

510-847-0474 jsoller@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 30 274 2937

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.john@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.govU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 B-5 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.denise@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.govU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 B-6 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.comU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 C-1 

## A PPENDIX 

## C: T RANSLATION OF 

## E PIDEMIOLOGY TO 

## D ISEASE


## B URDEN BY 

## WHO AND 

## EU

In a series of five international expert c onsultations 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 expe rts, have developed a methodology for expressing the exposure-risk relationship for recrea tional 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 ba sed on the following two assumptions:

1. that the statistical distribution of the fecal i ndicators (i.e., given a sufficiency of samples through a compliance period such as a bath ing season) which predict illness in recreational waters is described by a log 10 -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 pr oportion of the exposed population that becomes ill) for any beach, regi on or jurisdiction can be calculated from the parameters of the pdf, principall y its geometric mean (GM) value (i.e., the mean of the log 10 transformed bacterial counts) and the standard deviation (SD) of the log 10 transformed bacterial

counts. The mathematical basis of these calcu lations is outlined in WHO (2003), while Kay et al. (2004) and Wyer et al. (1999) provide a discussion on the imp acts of different GM and SD assumptions.

Figure C-1 illustrates a theoretica l 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 dur ing 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 a bove 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.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 C-2 Figure C-1. A Probability Density Function of

Fecal Indicator Distributions Measured at a Recreational Water Showing Probability of Exposure (Y Axis) versus Log10 Fecal Streptococci Concentration (later termed enterococci).

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. 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

1.0 1.5 2.0 2.5 3.0 3.5 4.0 log 10 enterococci (per 100 ml) 0 5 10 15 20 25 30

-2 -1 0 1 2 3 4 log 10 faecal streptococci (cfu/100 ml) log 10 Mean = 1.176 log 10 SD = 0.751



### a

bU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 C-3 Figure C-3 combines the pdf of Figure C-1 with the dose-response curv e of Figure C-2 to produce a relative disease burd en prediction as a proportion of the exposed population. The mathematical basis of this proce ss is provided in Kay et al. (2004).

Figure C-3. Combining the Dose-response Curve and the pdf

to Produce a Relative Diseas e Burden Assessment for any Beach or Region. 4 0 1 2 3 4 5

-3 -2 -1 0 1 2 3 log 10 enterococci (per 100 ml)

Mean = 0.9337 (geometric mean = 9 enterococci per 100 ml)
Standard Deviation = 0.8103

95 th percentile = 2.2672 (185 enterococci per 100 ml) Excess probability of illness = 0.05 Probability density function

Dose response curve Proportion with illness 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 C-4 The computation of gastrointestinal (GI) illn ess rates in the population is accomplished as follows. The pdf is described by:

2 2

2 ) (

2 1

s m c e

s y − −

=

π

Where c is the log 10 transformed enterococci concentration, y is the normal curve height, and m is the mean enterococci concentration. The as sociated probability of exposure across a given range of enterococci concentration (i.e., c a to c b ,) for a given distribut ion is expressed by:



## ∫

= Φ cb

ca dc

y c ) (

which is the area under the normal pdf curve between the limits c a and c b . The proportion of

bathers with GI illness is then calculated from the area under the curve described by:

p y z =

where p is the probability of GI i llness (gastroenteritis) from th e dose-response relationship with the upper limit set at 158 ente rococci per 100 mL; that is:

3561

. 2 ) 9

. 31 ( 20102

. 0

− − = c p

and z is the corresponding proportion of the normal curve height, y . The associat ed probability of GI illness across the range of enterococci concentrations, c a to c b , is then expressed by the following integral:



## ∫

= Φ cb

ca dc

z c ) (

For the WHO (2003) Guidelines derivation, the in tegration 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; Wy er, MD; Godfree, AF; Zelenauch-Jacquotte, Z; Shore, R. 1994. Predicting the likelihood of gast roenteritis from sea bathing – Results from randomized exposure. The Lancet 344: 905-909.

Kay, D; Bartram, J; Pruss, A; Ashbolt, N; Wy er, MD; Fleisher, JM; Fe wtrell, L; Rogers, A; Rees, G. 2004. Derivation of numeri cal values for the World Health Organization guidelines for

recreational waters. Water Research 38: 1296-1304.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 C-5 Khabaza, IM. 1965. Numerical Analysis . London: Pergamon 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 experime ntal health-related cl assification for marine

waters. Water Research 33(3): 715-722.[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 D-1 

## A PPENDIX 

## D: S UMMARY OF THE 

## E UROPEAN 

## C OMMISSION


## D IRECTIVE

Revised Bathing Water Directive (EP/CEU, 2006)

The Directive sets out requi rements for the following:

(a) the monitoring and classificati on 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 Un ion (EU) bathing waters used by “large numbers”

of bathers which must be asse ssed against the criteria in Table 2 in Chapter 1 of these proceedings (using the previous 3 or 4 years of sampling data) tho ugh 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 greates t numbers of bathers might be expected (Article 3.3b). Member States must monitor each bath ing water in accordance with a monitoring calendar established at the start of the bathing seas on (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) pr ovided that Member States comply with the additional provisions outlined below.

Bathing waters are legally required to achie ve “sufficient” microbi ological 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 en sure 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 pr event, 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 cau ses of the pollution and measures taken, on the basis of the bathing water profile.

Member States must establish their bathi ng 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;U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 D-2 • 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 s hort-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 b ecause of such pollution, and a warning whenever such pollution is predicted or present;

• information on the nature and expected dur ation 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 techno logies, including the Internet, to disseminate actively and pr omptly the information concerning bathing waters referred to in paragraph 1 and also the following information in several languages, when appropria te” (Article 12.1 and 12.2).

Where a bathing water is subjec t to short-term pollution the pub lic 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 wate rs beginning March 24, 2008.

Member States are free to simply use the numeri cal 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 bathin g water profile and have complied with the requirement to provide public information specif ied 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 disco unted in this manner prior to the calculation of the compliance statistics.

References

EP/CEU (European Parliament/C ouncil of the European Union). 2006. Directive 2006/7/EC of the European Parliament and of the Council of 15 February 2006 Concerning the Management ofU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 D-3 Bathing Water Quality and Re pealing Directive 76/160/EEC. Official Journal of the European

Union L64: 31-51. Available at: http://europa.e u.int/eur-lex/lex/LexUri Serv/site/en/oj/2006/ l_064/l_06420060304en00370051.pdf.[this page intentionally left blank]U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 E-1 

## A PPENDIX 

## E: I NDICATOR 

## T ERMINOLOGY

Table E-1. 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 heterotroph ic bacteria or total coliforms

for chlorine disinfection Fecal indicator A group of organisms th at indicates the presence of fecal contamination, such as the bact erial groups fecal coliforms or

E. coli ; thus, they only infer that pathogens may be present Index and model organisms A group/or speci es 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 be longing 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 pr otozoa), 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-1 for definitions of microbial groups (adapted from Ashbolt et al., 2001).

Text Box E-1. Definitions of Ke y Fecal Indicator Microorganisms

Coliforms : Gram-negative, non spore-forming, oxidase- negative, rod-shaped facultative anaerobic bacteria that ferment lactose (with β -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 β -glucuronidase (although taxonomically 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 co cci 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% methylen e 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 aerobi c growth at 44±0.5°C and of hydrolysing 4- methlumbelliferyl- β -D-glucoside (MUD, detecting β -glucosidase activity by blue florescence at 366nm), in the presence of thallium acetate, nalidixic acid, a nd 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 H 2 S.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 E-2 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 presen t 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 branch ed acids, (b) saccharolytic, producing acetate and succinate as the major metabolic end products; (c ) contain enzymes of the hexose monophosphate shuntpentose 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 meso -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 closel y 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. I ndicators of Microbial Water Quality. Pp: 289-

316 in: Water Quality: Guidelin es, Standards and Health Fewtrell, L; Bartram, J. (eds.). London: IWA Publishing.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 F-1



## A PPENDIX 

## F: S UMMARY OF 

## M EASUREMENTS 

## C URRENTLY 

## P LANNED

FOR THE 

## D OHENY AND 

## M ALIBU 

## B EACH 

## (C ALIFORNIA 

## )

E PIDEMIOLOGY 

## S TUDY

Table F-1. Summary of Measurements Curr ently Planned for the Doheny and Malibu Beach (California) Epidemiology Study.

Indicator Method Investigator

Traditional

Enterococci IDEXX South Orange County Wastewater Authority (SOCWA)

Enterococci Membrane-filtration (MF) SOCWA

Fecal coliforms MF SOCWA

E. coli MF or IDEXX Southern California Coastal Water Research Project (SCCWRP)

Total coliforms MF SOCWA

Rapid Traditional

Enterococci Quantitative polymerase chain reaction (qPCR) Noble Enterococci qPCR Stewart

Enterococci PCR-Luminex Stewart Enterococci Transcription-mediated amplification/nucleic acid sequence-based amplification (TMA/NASBA) Moore

Enterococci Immunomagnetic separation (IMS) Bushon

E. coli qPCR Noble

E. coli IMS Bushon

E. coli IMS Jay

Marker Genes Entero-Raptor, Esp gene qPCR-Raptor Harwood/Lim

Enterococci Esp gene qPCR Scott

E. coli virulence genes qPCR Sadowsky

Bacteroides human marker qPCR Field

Bacteroides human marker qPCR Wuertz

Phage Phage Culture Stewart Phage Culture Sobsey Rapid phage Antibody Sobsey

Human Virus Adenovirus qPCR SobseyU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 F-2 Indicator Method Investigator
Enterovirus qPCR Stewart Hepatitis A virus qPCR Fuhrman Norovirus qPCR Stewart Norovirus qPCR Sobsey Polyomavirus qPCR Harwood

Community Profiling

Bacteroides

thetaiotamicron Sequencing Moorthy Heliobacter pylori Sequencing Moorthy Campylobacter jejuni Sequencing Moorthy Clostridium perfringens Sequencing Moorthy

Salmonella enteritica

serovar Typhimurium Sequencing Moorthy Shigella dysenteriae Sequencing Moorthy Shigella flexneri Sequencing Moorthy Shigella boydii Sequencing Moorthy

Bacterial Markers

Bacteroides thetaiotamicron qPCR Noble

Bacteroides thetaiotamicron PCR Leddy Multiple methanogens PCR Ufnar

Methanobrevibacter smithii PCR-Luminex Stewart

Methanobrevibacter smithii qPCR Stewart Legionella spp. qPCR GastU.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 G-1 

## A PPENDIX 

## G: D EVELOPMENT OF 

## D ETERMINISTIC 

## M ODELS

The discussion of the modeling workgroup member s included the present and future use of statistically-based models. This relates to th e fact that they are currently being used to supplement monitoring information and can be im plemented 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 repr esents a longer-range measure that might be considered in the contex t of research and development beyond the 2 to 3 year (near-term) window envision ed by the current criteria devel opment effort; however, there were differences of opinion on the importance of th is relative to development of new or revised recreational water qua lity criteria.

Although not discussed in detail at this worksho p, deterministic process-based models represent an entire range of additional m odeling 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 th at consider other fact ors such as sediment resuspension, hydrodynamics, micr obial growth and decay, and non -point source basin scale inputs. For example, a process-based deterministi c model has been recently used to predict fecal

indicator concentrations in coas tal reaches of southern Lake Michigan (Liu et al., 2006) and Huntington Beach, California (Boe hm et al., 2005; Grant et al., 2005). Deterministic models also are being used in the development of to tal maximum daily loads (TMDLs) for pathogens and in evaluations of non-pointand sources of biological cont aminants in watersheds.

In this appendix, deterministic models for ev aluating pathogens in wa tersheds are briefly discussed. TMDLs often have to consider non-po int 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 di scretize the watershed sp atially and bacteria loads spatially and temporally, al though 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 TM DL process. The load duration method of developing TMDLs provides a good representati on of overall water quality and needed water quality improvement, but intra-waters hed bacteria contributions must be determined through supplemental sampling or through subsequent hydrologic and water quality modeling. Identified research n eeds include improved bacteria source characterization procedures and supporti ng data, and specific modeling advances.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 G-2 New models are now becoming available for eval uating non-point sources of pathogens derived

from watersheds and catchments.

• The L-THIA model (http://www.ecn.purdue.edu /run-off/lthianew/) combined with GISreferenced inputs from Digital Watershed are being used as tools to evaluate runoff of fecal coliform and fecal streptococcus (enter ococci) 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 cha nges and potential best management practices (BMPs) for quality and quantity for the bact eria. L-THIA will be directly linked to STORET water quality and SSURG O 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/sparro w/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 ev aluate the following indicators: fecal coliforms, E. coli

, C. perfringens , somatic coliphage, F+ R NA phage, and the bacterial pathogen Campylobacter . The explanatory data for th e SPARROW models include land

use and other data that descri be the climatic, hydrologic, and physical conditions of the

catchments. The models also reveal the eff ects 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 wa ter 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/lspc.html).

In addition to these models, a 1999 EPA report descri bes 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 th at is included in the BASINS3 watershed model system that is maintained by EPA (h ttp://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 m odel of enterococci inactivation, grazing, and transport in the surf zone of a marine beach. Water Research 39(15):

3565-3578.U.S. Environmental Protection Agen cy Experts Scie ntific Workshop

June 2007 G-3 Grant, SB; Kim, JH; Jones, BH; Jenkins, SA ; Wasyl, J; Cudaback, C. 2005. Surf zone entrainment, along-shore transport, and human hea lth implications of pollu tion 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 transpor t and inactivation of E. coli and enterococci in th e 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. Wa shington, DC: US

EPA.