&EPA
United States
Environmental Protection
Agency
Ottice ot Hesearcn ana
Development
Washington, DC 20460
EPA 600 9-90 021
September 1990
Workshop on
Methods for
Investigation of
Waterborne Disease
Outbreaks
Summary of
Recommendations
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EPA 600'9-90 021
September 1990
Workshop on Methods for
Investigation of Waterborne Disease
Outbreaks
Summary of Recommendations
OctfrBer 11-13,1988
fHotel, Tabor Center
mver, Colorado
I Gunther F. Craun, Project Officer
f.S. Environmental Protection Agency
and
Janet L. McGoldrick, Project Manager
Association of State Drinking Water Administrators
Health Effects Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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Disclaimer
This document has been reviewed in accordance with U.S Environmental
Protection Agency policy and approved for publication Mention of trade
names or commercial products does not constitute endorsement or
recommendation for use.
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WORKSHOP ON METHODS FOR INVESTIGATION OF
WATERBORNE DISEASE OUTBREAKS
Planning Committee
Gunther Craun
Chief, Population Studies Section
Health Effects Research Laboratory
US Environmental Protection Agency
Wade Miller, Executive Director
Association of State Drinking
Water Administrators
Janet McGoldrick
Deputy Executive Director
Association of State Drinking
Water Administrators (ASDWA)
Stuart Castle
Program Manager. Drinking Water Section
New Mexico Health and Environment Department
Richard Vogt
Epidemiologist
Vermont Department of Health and
Member, Council of State and
Territorial Epidemiologists
Nathan Schaffer
Medical Epidemiologist
Bacterial Diseases Division
US Centers tor Disease Control
Peter Karalekas, Chief
Public Water Supply Section, Region I
US Environmental Protection Agency
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Table of Contents
Pac
Planning Committee
Introduction
Recommendations 2
Appendices
Appendix A: Workshop Program 12
Appendix B: Abstracts of Presentations 19
Appendix C: Listing of Participants 44
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Introduction
The Environmental Protection Agency's (EPA) Health Effects Research
Laboratory and the Association of State Drinking Water Administrators
(ASDWA) planned and conducted a workshop for state epidemiologists and
drinking water officials in October 1988. for the purpose of improving the
investigation and reporting of waterborne disease outbreaks. Additional and
more accurate information is needed on the causes of waterborne outbreaks.
Such data will enable researchers to evaluate the adequacy of current
regulations, surveillance activities, water treatment practices, and source water
protection policies.
The workshop brought together research scientists, epidemiologists.
engineers, and microbiologists from government and academe to discuss and
exchange information on outbreak investigations including analytical
procedures, water supply engineering, surveillance, and other related regula-
tory activities. A goal of the workshop was to improve communication among
outbreak investigation personnel.
Plenary sessions provided participants with basic concepts in
epidemiology, water supply engineering, clinical and water sample collection
and analyses. Examples of several recent outbreak investigations were
included to reinforce these concepts and to provide an understanding of the
investigative process. More detailed discussions were held during breakout
sessions. Articles based on the presentations will be published as a separate
volume by the EPA.
The latter portion of the workshop was designed to allow for the
identification of research, training, and other requirements needed to prevent
waterborne outbreaks as well as improve their recognition, investigation, and
reporting. Through the breakout sessions and through audience participation.
a number of recommendations were made. The recommendations are
summarized on the following pages. A copy of the workshop program is also
included in Appendix A. Abstracts of presentations are contained in Appendix
B and a listing of participants is included in Appendix C.
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.
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Recommendations
Breakout session chairpersons and speakers met following their
respective sessions to discuss various issues brought forth ana to deveioo
recommendations based upon audience discussion and participation The
recommendations were then presented to all workshop participants through a
series of panel discussions. The audience was provided an opportunity 10
expand upon these issues and recommendations. A summary of the
recommendations by subject area is included below.
I. General Recommendations
1) Workshop participants identified a need for increased funding for:
a) laboratory support, particularly for those agents which are difficult
to identify;
b) field investigation personnel in order to adequately respond to
outbreaks; (It was noted that multi-disciplinary teams are required
to provide the expertise needed to handle the types of outbreaks
that are typically occurring. It was recommended that additional
resources be available to EPA and Centers for Disease Control
(CDC) officials to provide technical assistance to the states for
outbreak investigations.]; and
c) computer resources at the state and local levels to assist with data
analysis.
2) The states requested that more laboratory support be made available
when requested of CDC and EPA to assist m the identification of
etiologic agents, especially those requiring specialized analysis. The
states also requested that EPA provide engineering evaluations of
outbreak situations as they did m the 1970s
II. How to Improve Outbreak Reporting, Disease Surveillance, and
Related Research Issues
Improved outbreak reporting and disease surveillance requires better
communication, coordination, and cooperation at local, state, and federal levels
between epidemiologists, drinking water authorities, and laboratory officials
The voluntary reporting of waterborne outbreaks should be continued with
increased efforts on improving collaboration among various agencies that
share responsibilities for investigation and reporting.
1) Designate a waterborne disease surveillance coordinator at CDC. EPA,
and in each state to act as the key link m communication between
agencies. These coordinators should be MPH-tramed. mid-level
epidemiologists or public health engineers and should be encouraged
to provide timely feedback m:
a) gathering and summarizing surveillance data.
b\ maintaining surveillance by reguSai contact with state health
departments.
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c) obtaining computer reports of epiderruoiogicai investigations: and
d) summarizing the pertinent data (or publication m annual
surveillance summaries, and scientific literature {Routine
distribution of these reports should be made to the states.)
2) Publish a directory of names, addresses and telephone numbers
including the surveillance coordinators, state drinking water
administrators, and state public health laboratory directors and send to
all individuals listed. The directory should be updated periodically
3) Hold periodic conferences such as this workshop to bring together
epidemiologists and drinking water personnel for the purpose of:
a) reviewing general trends and recent outbreaks of waterborne
disease:
b} discussing the need for changes in control efforts;
c) considering future research priorities;
d) improving communication between the two groups:
e) generating new ideas; and
f) introducing new personnel to the complexities of waterborne
outbreaks.
4) Create a working group to redesign the current waterborne outbreak
reporting form to require the following:
a) additional detail on the nature of the affected water supply system
and on the specific type of treatment being used:
b) specific information on water quality including coliform and
turbidity data and treatment before as well as during an outbreak;
c) additional detail on contributing factors relating to problems m
filtration as well as disinfection; and
d) more easily codable answers.
5) Promote the electronic transmission of surveillance data as a long-term
goal. Such an approach will establish an interactive on-line data base
from which public health officials can both enter and extract data
rapidly.
6) Encourage laboratory based surveillance of potential waterborne
diseases where feasible, including Giardia and Cryptosporidium.
7) Assuming the ultimate goal of reducing the number of waterborne
disease outbreaks is successful, other outcome measurements {i.e.,
rare outbreaks will become more difficult to use as gauges) are
necessary to monitor the successful control program. Potential
measures include:
a) population covered;
b) percent of surface water systems using filtration;
c) percent of groundwater systems using disinfection.'filtration;
d) percent of systems participating in continuing education programs;
and
e) measures of operator knowledge and competence.
8) As with any surveillance system, the data collected represent a
balance between the essentials required and the desire to keep the
investigation process as shorl as possible However, specific special
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studies can be conducted-collecting more information about reported
outbreaks over a shorter period of time. These specific studies can be
viewed as a "base" for later, more detailed investigations Examples of
some potential investigations include.
a) relating outbreak data to the denominator of all water supply
systems: and
b) comparing the characteristics of operators of supply systems
involved in outbreaks with those of al! opera tors
It). How to Improve Epidemiological Investigations and Related
Research Issues in Epidemiology Methods
Perhaps the most important issue discussed was the fact that only 50
percent of the waterborne outbreaks are investigated thoroughly enough to
establish an etiotogic agent. It was recommended that additional research be
conducted to identify the etiologic agents involved in waterborne outbreaks
that are now classified as "unknowns." This would require increased labora-
tory support and quicker recognition of potential outbreaks so that timely
samples could be collected. Until the etiologic agents are identified, one
cannot assess the appropriateness of technologies to mitigate occurrence.
Such an awareness was identified as critical given EPA's current position of
promulgating regulations under the 1986 Safe Drinking Water Act (SDWA)
Amendments.
1) Field personnel must be more thoroughly trained. Attention needs to
be given to the type of training that should be provided and the means
through which it can be given [It was noted that formal training for
epidemiologists previously provided from the CDC has been useful
Concern was expressed that adequate resources may not be applied
for such training in the future. It was requested that the record reflect
the recommendation that CDC continue training efforts m this area ]
The need for brief but substantive training for water supply engineers
in the area of epidemiology and for laboratory personnel in the area of
outbreaks was also identified.
2) An information network that identifies the critical issues to be investi-
gated during specific outbreaks should be established for research
personnel. [A network to allow state and federal officials to
communicate aspects of particular investigations that may be useful to
others was noted as a need. Some mechanism for following through
on whether approaches to mitigating public health risks due to
outbreaks (i.e.. boil water notices) are successful was also identified as
a need.)
3) Questionnaires used during outbreak investigations should be included
with final reports. Such a practice will aid m the evaluation and
interpretation of epidemiologic data Further recommendations
concerning the survey instrument included:
a) a list of the minimum data set(s) required to be gathered for each
type of outbreak investigation should be compiled, the lists would
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serve as useful aids during the hectic moments of outbreak in-
vestigations; and
b) investigators should be cognizant that methods for evaluating
outbreaks are crude at best: investigators should not be placed m
a position to apologize for the lack of tools or to make current tools
seem more sophisticated.
[It was noted during discussion that CDC has a software package
available to aid in the development of survey instruments and m the
ensuing analyses. Although the user must write his her own
questionnaires, some thought has been given to providing sample
surveys with future upgrades of the software. The software is
compatible with IBM and is available for approximately S18 from the
CDC.]
4) The results of outbreak investigations should be made available to the
appropriate water supply operators in a timely manner to avoid future
occurrences. Investigation reports should also be utilized as education
tools with water supply operators. One suggestion was to occasion-
ally survey operators regarding their knowledge of outbreak
occurrence.
5) The media should be utilized as a vehicle for:
a) improving case ascertainment during the investigation period (i.e.,
by publicizing outbreaks, the public may be more encouraged to
seek medical attention and, therefore, be counted); [Some
workshop participants expressed concern in this area and noted
that publicity may introduce biases into the data collection
process; others, however, noted that the media should not be
relied upon only in emergency situations. In other words, a
relationship should be built and supported between research reg-
ulatory personnel and the media on a daily basis.], and
b) in advising the public of actions they may (should) take during
specific outbreaks (i.e.. boil water notices, etc.).
IV. How to Improve the Collection and Analysis of Clinical and
Environmental Samples
There is a large category of etiological agents associated with waterborne
outbreaks which are unidentified partly because of 11nadequate sample
collection; 2) inadequate analysis; and 3) non-recognition of agents as the
cause of disease.
There is also a lack of resources for both clinical and environmental
sample analysis. Specific needs are a) protocols for specimen and sample
collection; b) personnel for collection of environmental samples; c)field
equipment for appropriate sampling; and d) laboratories which can recover
and identify the variety of bacteria, protozoa and viruses which may be the
cause of a specific outbreak.
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1) Epidemiologists must keep abreast of newly identified entenc
organisms which have the potential for causing waterborne disease
such as:
a) caliciviruses;
b) Small Round Viruses (SRV);
c) Mycobactena:
d) Isospora; and
e) enteric non-A, non-B hepatitis virus(es).
2) Improvements in the collection of clinical samples which will facilitate
agent identification include:
a) early collection immediately at the onset of illness (within the first
24-48 hours);
b) large volume of fecal samples;
c) storage of fecal samples at 4 degrees Centigrade;
d) fecal samples sent to laboratories as soon as possible after
collection;
e) fecal samples separated and stored for various type analyses (for
various types of agents); and
f) collection of blood samples if possible (serological specimens
would not be required to be collected as quickly as stool samples;
research is needed to detect agents through serological analysis).
3) Recommendations for environmental sampling include:
a) collect samples as soon as outbreak is identified;
b) collect minimum of three replicates from individual source (well) or
eight to 10 samples from distribution system, including
c) sample for broad range of microorganisms;
d) collect a minimum of one liter for bacteria and 400 liters for viruses
and parasites; and
e) include, if possible, an environmental microbiologist with proper
experience for field sampling on the investigation team.
4) There should be improved communication and coordination between
laboratories, state health agencies and the CDC regarding:
a) whether information on appropriate procedures is available:
b) the prioritization and urgency of sampling; and
c) the use of laboratories as active participants in investigations as
opposed to service entities.
5) A list of contacts for laboratory support should be compiled. The list
should include guidance for appropriate laboratory quality assurance
and quality control procedures. An individual or organization needs to
be identified to update the list periodically and to distribute to
appropriate officials (i.e., state and federal epidemiologists, microbio-
logists and engineers).
6) States need to identify additional sources of laboratory support and
communicate with such entities to ensure that the most up-to-date and
progressive techniques are being used. Such sources of additional
laboratory support may include:
a) universities.
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b) private companies;
c) large utilities;
d) other state facilities; and
e) federal laboratories.
7) There is a need for a central agency or group to disseminate
information regarding 1ield sampling and sample analysis. Little or no
contact exists between laboratory microbiologists and the officials
being served (i.e., state and federal regulators). One suggestion is that
the states should work m conjunction with EPA regional offices to
develop information and communication networks.
8) The coliform standard as written is inadequate to assess the microbial
quality of water. The standard has limitations for some bacteria!
pathogens; also, the absence of coliforms does not indicate the
absence of viruses or parasites. It was recommended that research
studies be planned and conducted to identify better or additional
indicator organisms.
9) Specific monitoring strategies can be developed prior to the
occurrence of an outbreak. The strategies should:
a) be incorporated into the sanitary survey;
b) include the testing of pilot plants; and
c) evaluate existing systems at risk (e.g., no filtration or poor
filtration).
One suggestion was made to require increased monitoring during cold
seasons since epidemics often occur during these periods.
10) Surrogates for treatment plant efficiency include:
a) particulate analysis;
b) Hartmanellid amoeba; and
c) bacteriophage. such as MS2 and F2.
These can be used to judge the efficiency of water treatment
processes and will supplement the routine monitoring of cofiforms.
11) The development and use of innovative technology and exploratory
methodologies for analysis should be encouraged.
One suggestion was made for research to evaluate the optimal type
of filtration media to use to concentrate water samples. Additional
research is also needed on the identification of various strains of
protozoa that are capable of infecting humans as well.
There is a shortage of reagents for virus testing and identification.
Current detection techniques rely upon the electron microscope
which requires one million particles per cubic centimeter (cc). When
humans shed such quantities, it is typically in the first two days of
illness. Unfortunately, samples are not often obtained during this
period. Moreover, samples taken at home are often stored at cold
temperatures which may distort the morphological characteristics of
the virus(es). A suggestion was made by some state officials that the
CDC inform state epidemiologists of the exact nature of samples they
wish to receive. The comment was made that states may not be
aware the CDC dessres samples in such large volume. Also.
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conflicting information has been received from the CDC regarding
storage temperatures. The Agency was asked to clarify these issues
and provide some form of protocol to the states.
12) Method efficiencies need to be assessed: funds are needed lor
methods development and the standardization of methods
13) Readiness for environmental sampling is necessary and needed
14) Research should be funded during outbreak occurrences The
knowledge gained during these real life situations will contribute
greatly to the investigation process. It was suggested that such
research practices, in the long run, are cost-effective.
IV. Prevention of Outbreaks Through Engineering Controls and Water
Quality Surveillance
Comments made under this subject heading are preventive in nature.
Breakout group participants noted that the preventive approach to engineering
and water quality issues will do more to mitigate waterborne disease outbreaks
than will a reactionary approach. Analysis of the cause of waterborne
outbreaks can provide information on adequacy of treatment technologies and
surveillance activities. Regulatory and preventive measures should be based
on these data.current surveillance efforts should also be evaluated to
determine if the routine testing for coliforms is effective in preventing
waterborne outbreaks and if additional indicators of water contaminants are
needed. The comments and recommendations made are organized accord-
ing to the topical subjects presented during the session. These comments are
followed by more general recommendations that resulted from group
discussion.
1) Sanitary surveys of public water systems should:
a) include a review of all aspects of operation and maintenance of
distribution systems,
b) include physical inspection of all above ground facilities and review
of operating records; and
c) evaluate cross-connection control programs.
2) Watershed protection programs should:
a) characterize the watershed(s) and contaminant sources:
b) identify goals and measures to control contamination;
c) consist of monitoring and evaluation components to provide
feedback on the effectiveness of controls;
d) be developed on a site-specific basis;
e) incorporate a multiple-barriers approach to achieing the best water
quality (not necessarily incorporate beaver control as part of the
management strategy): and
f) address all surface supplies (not just unfiltered systems) to obtain
the best water quality possible
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3) Treatment plant evaluations should focus on:
a) facilities and their condition;
b) operating procedures:
c) water quality;
d) collecting samples in instances when complaints of illness have
been made (although not very practical); and
e) disinfection needs to be carefully designed to maximize its efficacy
as a unit process.
4} With respect to the determination of chlorine contact time (Ct) values,
comments such as the below were made;
a) Ct values are based upon limited data sets;
b) Ct values are included in EPA's Surface Water Treatment Rule
(SWTR);
c) the majority of G/ard/a/chlorine data for Ct values are based on
Hibler's data which leads to conservative values;
d) there is a need to investigate mechanisms to combine data sets to
find less conservative Ct values;
e) a need exists for continued research in the area of Ct values,
Giardia strain varieties and the organisms' resistance to chlorine;
f) additional Ct data is needed for eg (disinfection research should
continue even after the T986 SDWA regulations have been
implemented; and
h) Ct values provide a good framework or method for looking at
inactivation but do not provide the best framework for reviewing
overall plant operation.
5) State regulatory agencies need to have specific requirements for the
sanitary protection of water distribution systems, including:
a) proper construction and maintenance of distribution storage
reservoirs; and
b) disinfection of new and repaired water mains.
6} States should have specific requirements that place responsibility on
water systems to conduct comprehensive cross-connection control
programs. Such programs should include:
a) a cross-connection survey and plan review by qualified specialists;
and
b) the testing of devices by certified backflow prevention device
testers.
7) Water quality in distribution systems caused by persistent coliform
occurrence problems pose a problem for some utilities in complying
with federal and state drinking water standards. In such instances,
factors to be examined should include:
a) effects of varying assimilable organic carbon (AOC) levels in
treated water on the organisms;
b) specific levels of AOC that are required to stimulate growth of
different coliform organisms;
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c) need for specific methods to inhibit coliform growth in systems
with colonization problems;
d) establishing the health significance of colonized conforms; if there
is no health threat, how does the utility resolve the compliance
issue; and
e) variations in water quality and corresponding health effects (wide
variations within distribution systems exist, particularly when water
comes from a variety of sources); such variations pose difficulties
in tracing waterborne disease outbreaks.
8) In the area of treated water quality versus coliform noncompliance
problems, the following comments were made:
a) there is no such thing as a "representative" sample;
b) the use of permanent sampling taps is probably okay; and
c) sampling all on one day per month is not recommended.
d) research is needed to develop new or additional indicators for
assessing water quality and health risks.
9) The design of distribution systems were discussed. The following
comments were made concerning this issue:
a) systems are designed for water distribution as opposed to water
quality; and
b) hydraulic design should be considered since it can influence water
quality (at least in large systems).
10) General recommendations include the following:
a) greater coordination is needed on both the state and federal levels
between various programs that affect watershed and source water
quality (especially between Clean Water Act and Safe Drinking
Water Act) personnel/agencies);
b) greater coordination is also needed between drinking water
regulators and sewage dischargers;
c) better communication and coordination regarding epidemiology,
regulation and monitoring o( public water systems is encouraged
at the state level;
d) a balance of resources must be sought between research,
technical assistance, and monitoring in drinking water regulatory
programs:
e) regulations should be compatible to the maximum extent possible
and view water systems as one entity;
f) regionalization of systems for physical connections or as a
management option for small systems should be promoted;
g) knowledge-transfer among the states should be promoted
especially with regard to handling non-community systems;
h) opportunities for the private sector in water supply should be
examined (i.e., sanitary surveys, laboratory certification, operator
10
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training, vulnerability assessments, etc.): potential problems
associated with this approach should be evaluated (i.e.. loss of
institutional memory, lack ol continuity, etc.);
i) training of state and local drinking water regulatory personnel
should be conducted (continue to be conducted) by EPA regarding
SDWA implementation;
j) finished water sources should be protected from contamination
(i.e., use of reservoir covers, etc.):
k) a mechanism for timely reporting of waterborne disease outbreaks
should be constructed and disseminated to regulatory and utility
personnel;
I) a major goal of drinking water regulatory efforts should be the
prevention of waterborne disease by concentrating on deficiencies
which have caused outbreaks and evaluating the effectiveness of
current water quality surveillance efforts (i.e. routine coliform
sampling) in preventing outbreaks: and
m) there is a need for basic research to be conducted at the federal
level and for the delivery of research findings in the form of
technical assistance to the states; while some states have continu-
ing experience with waterborne disease outbreaks and
investigations, other states are not in such a position and require
the knowledge base developed by other states and the federal
government.
11
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APPENDIX A
WORKSHOP PROGRAM
12
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Workshop on Methods for Investigation of Waterbornc
Disease Outbreaks
October 11-13. 1988
The Westm Hotel. Tabor Center
Denver, Colorado
Final Schedule of Events
TUESDAY, OCTOBER 11
10:00 a.m. REGISTRATION (Foyer) to 12:30 p.m.
OPENING SESSION
Tabor Auditorium
Session Moderator. Stuart P. Castle, ASDWA and New Mexico Environmental
Improvement Division
12:30p.m WELCOME
Stuart P. Castle
12:35 p.m. WORKSHOP OBJECTIVES
Gunther F. Craun, EPA
12:45 p.m. REVIEW OF CURRENT WATERBORNE DISEASES
Gunther F. Craun
1:10 p.m. THE 1986 SDWA AMENDMENTS AND DRINKING WATER
REGULATIONS
Paul S. Berger and Stig E. Regli, EPA
SURVEILLANCE FOR WATERBORNE ILLNESS AND DISEASE
REPORTING:
1:45 p.m Federal Responsibilities and Requirements
Robert V. Tauxe, CDC
2:00 p.m. State and Local Responsibilities
Lawrence R. Foster, Oregon Health Division
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2:15 p.m. EPIDEMIOLOGIC METHODS FOR THE INVESTIGATION OF
WATERBORNE DISEASES
Richard L. Vogt. Council of State and Territorial Epidemiologists
and Vermont Departmenl of Health
PRINCIPLES OF WATER FILTRATION AND DISINFECTION:
3:00 p.m. Principles of Water Filtration Gary S. Logsdon. EPA
3:30 p.m. Principles of Drinking Water Disinfection
John C. Hoff, EPA
4:00 p.m.l INVESTIGATION OF OUTBREAKS EMPHASIZING
ENGINEERING/EPIDEMIOLOGY INTERACTIONS
Edwin C. Lippy, US Public Health Service-Retired
4:30 p.m. ENVIRONMENTAL SAMPLING METHODS. LIMITATIONS AND
DATA INTERPRETATION
Joan B. Rose, University of Arizona
5:00 p.m. DISCUSSION
WEDNESDAY, OCTOBER 12
SESSION TWO: CASE STUDIES
Tabor Auditorium
Session Moderator: Peter C. Karalekas Jr.. EPA
CRYPTOSPORIDIUM OUTBREAK IN CARROLLTON. GEORGIA:
8:30 a.m. Epidemiologic Characteristics of Waterborne Cryptosporidiosis
Dennis D. Juranek, CDC
9:00 a.m. Troubleshooting an Existing Treatment Plant
Gary S. Logdson, EPA
9:30 a.m. Discussion
9.45 a.m. CHRONIC DIARRHEA IN HENDERSON COUNTY. ILLINOIS
JuSie Parsonnet, CDC
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WATERBORNE GIARDiASIS IN PITTSFIELD,
MASSACHUSETTS:
10:30 a.m. Epidemiologic Perspective
George P. Kent. Stanford University School of Medicine
(formerly with CDC)
11:00 a.m. Engineering Perspective
John J. Higgins, Massachusetts Department of Environmental
Quality Engineering
11:30 a.m. Discussion
11:40 a.m. AN OUTBREAK OF ICE-RELATED NORWALK
GASTROENTERITIS: PENNSYLVANIA AND DELAWARE
Jay R. Poliner, Eastern New York Occupational Health Program
(formerly with CDC)
12:10 p.m. COMMENT: EXTENDING THE SPECTRUM OF WATERBORNE
VIRAL DISEASES
Charles W. LeBaron. CDC
12:20 p.m. Discussion
THREE CONCURRENT BREAKOUT SESSIONS
BREAKOUT SESSION A: EPIDEMIOLOGY METHODS
Lawrence Room A
Chairwoma. Patricia A. Murphy, EPA
Rapporteur: Gayle J. Smith. Utah Department of Health
2:00 p.m. AVOIDING BIAS: SYSTEMATIC AND RANDOM ERROR Patricia
A. Murphy
2.30 p.m. DEVELOPMENT OF DATA COLLECTION INSTRUMENTS:
QUESTIONNAIRES AND INTERVIEW SCHEDULES
Charlotte A. Cottrill. EPA
3:00 p.m. DATA ANALYSIS: ESTIMATING RISK
Neal D. Traven, University of Pittsburgh
3.30 p.m. DATA INTERPRETATION: DIFFERENCES BETWEEN
OUTBREAK INVESTIGATION AND RESEARCH
EPIDEMIOLOGY
Neal D Traven
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4:00 p.m. EMERGENCY RESPONSE AND CONTROL MEASURES
Gayle J. Smith
4.30 p.m. DISCUSSION
BREAKOUT SESSION B. ENGINEERING AND WATER
QUALITY CONCERNS
Lawrence Room B
Chairman: Gary S. Logsdon, EPA
Rapporteur: Stuart P. Castle, ASDWA and New Mexico Environmental
Improvement Division
2:00 p.m. SURFACE WATER SOURCE PROTECTION
Joseph L. Glicker, Portland Water Bureau
2:15 p.m. DISTRIBUTION SYSTEM PROTECTION
Peter C. Karalekas Jr., EPA
2:30 p.m. EVALUATING WATER TREATMENT PLANT DESIGN AND
OPERATION
Gary S. Logdson
3:00 p.m. DETERMINATION OF CT VALUES
Robert M. Clark. EPA
3:30 p.m DISTRIBUTION SYSTEMS: TREATED WATER QUALITY
VERSUS COLIFORM NON-COMPLIANCE PROBLEMS
Robert M. Clark
4.30 p.m. DISCUSSION
BREAKOUT SESSION C: ANALYSIS OF CLINICAL AND
ENVIRONMENTAL SAMPLES
Curtis Room
Chairwoman: Joan B. Rose, University of Arizona
Rapporteur: Frank W. Schaefer III, EPA
LABORATORY SUPPORT FOR CLINICAL SAMPLES
2:00 p.m. Bacterial
Julie Parsonnet, CDC
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2:30 p.m. Protozoan
Dennis D. Juranek. CDC
3:00 p.m. Viral
Charles W. LeBaron. CDC
LABORATORY SUPPORT FOR WATER SAMPLES
3:30 p.m. Analysis of Water Samples for Bacterial Pathogens
Gerard N. Stelma Jr., EPA
4:00 p.m. Virological Analysis of Environmental Water Samples
Christon J. Hurst, EPA
4:30 p.m. Analysis of Water Samples for Protozoa
Jan L. Sykora. University of Pittsburgh
5:00 p.m. DISCUSSION
THURSDAY, OCTOBER 13
PANEL SESSIONS
Tabor Auditorium
Session Moderator: Janet L. McGoldnck, ASDWA
8:30 a.m. HOW TO IMPROVE EPIDEMIOLOGIC INVESTIGATIONS.
EMERGENCY RESPONSE. AND RELATED RESEARCH
ISSUES
Chairwoman: Patricia A. Murphy
Panel Members:
Charlotte A. Cottrill
Laurence R. Foster
Julie Parsonnet
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9:15 a.m. HOW TO IMPROVE ENVIRONMENTAL AND CLINICAL
SAMPLING.ANALYSIS. AND RELATED RESEARCH ISSUES
Chairwoman: Joan B. Rose
Panel Members:
Charles W. LeBaron
Chnston J. Hurst
Frank W. Schaerfer III
Gerard N. Stelma Jr.
Jan L. Sykora
Jay Vasconcelos
10:15 a.m. PREVENTION OF WATERBORNE OUTBREAKS, SDWA
IMPLEMENTATION ISSUES, AND RELATED RESEARCH
ISSUES
Chairman: Gary S. Logsdon
Panel Members:
Stuart P. Castle
Robert M. Clark
Joseph L. Glicker
John C. Hoff
Peter C. Karalekas Jr.
Donald J. Reasoner
Stig E. Regli
11:15 a.m. HOW TO IMPROVE OUTBREAK REPORTING. DISEASE
SURVEILLANCE, AND RELATED RESEARCH ISSUES
Chairman: Robert V. Tauxe
Panel Members:
Paul S. Berger
Guniher F. Craun
Dennis D. Juranek
Richard J. Karlin
Richard L. Vogt
12:00 noon WORKSHOP SUMMARY
Stuart P. Castle, ASDWA and Gunther F. Craun, EPA
12:15 pm ADJOURNMENT
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APPENDIX B
ABSTRACTS OF PRESENTATIONS
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Workshop Objectives. GUNTHER F. CRAUN (Health Effects Research
Laboratory, US Environmental Protection Agency. Cincinnati. OH).
Only a fraction of the waterborne outbreaks that occur m the United States
are recognized, investigated, and reported, and for those outbreaks that are
reported, an etiologic agent is identified in only half of them. The primary
purpose of this workshop is to improve the investigation and reporting of these
outbreaks so that better information will be available on their causes. This
information is necessary to determine the adequacy of current surveillance
and regulations to prevent the waterborne transmission of disease. The
identification of etiologic agents is important to evaluate current water
treatment technologies and source water protection policies.
The workshop brings together research scientists, epidemiologists.
engineers, and microbiologists from government and academe to discuss and
exchange information on outbreak investigations, analytical procedures, and
water supply engineering, surveillance and regulatory activities. Improved
communication is needed among the various disciplines and agencies that
share responsibilities in the investigation and prevention of waterborne
outbreaks.
Plenary sessions were developed to provide participants with basic
concepts and knowledge of epidemiology, water supply engineering, and
clinical and water sample collection and analyses. Examples of several recent
outbreak investigations serve to reinforce this knowledge and provide an
understanding of the investigative process. More detailed discussions of each
of these areas wd! be presented in the breakout sessions. Articles based on
the presentations will be published in a reference volume which will be made
readily available to assist in the investigation of outbreaks.
The last part of the workshop is devoted to identifying research, training.
and other requirements to prevent waterborne outbreaks and improve their
recognition, investigation, and reporting. These recommendations are
developed through panel discussions and audience participation and
published in a separate report.
Review of Current Waterborne Diseases. GUNTHER F. CRAUN (Health
Effects Research Laboratory. US Environmental Protection Agency, Cincinnati.
OH).
The reporting of waterborne disease outbreaks has been and continues to
be voluntary. Statistical data are available on water outbreaks reported in the
United States since 1920. These data are compiled from information obtained
from the scientific literature and through the assistance of state and loca!
health officials and engineers. The Environmental Protection Agency and
Centers for Disease Contro! have cooperated in the investtgation and reporting
of waterborne outbreaks since 1971.
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The incidence of waterborne disease in the United States has declined
from about eight cases per 100,000 person-years during 1920-40 to four cases
per 100.000 person-years during 1971-80. The number of outbreaks reported.
however, has not declined, and more waterborne outbreaks were reported
during 1971-85 than in any previous 15 year period since 1920. During 1971-
1985. 502 waterborne outbreaks and 111.228 cases of iHness were reported m
49 slates and Puerto Rico and the Virgin Islands. Almost three fourths of
these outbreaks were caused by use of contaminated, untreated or
inadequately treated groundwater and surface water. Waterborne diseases in
the United States are transmitted by the fecal-oral route of exposure, and it is
important to recognize that contaminated drinking water is only one of several
sources of infection. An epidemiologic investigation is necessary to establish
the probable cause of illness. Giardia lamblia has been the most commonly
identified pathogen in waterborne outbreaks since 1971, and contaminated
drinking water is a significant source of infection for giardiasis. Human
sewage contamination was primarily responsible for the traditional waterborne
diseases such as typhoid fever; however, for several of the more recently
identified waterborne diseases such as giardiasis, wild and domestic animals
have also been found to be an important primary or intermediary source.
Current drinking water regulations are insufficient to prevent the
waterborne transmission of infectious disease, as outbreaks have occurred m
water systems that have not exceeded current regulations for coliforms and
turbidity. Analysis of data from outbreaks in surface water systems shows the
need for filtration in addition to disinfection to ensure the removal and
inactivation of waterborne pathogens, especially protozoa such as Giardia.
Properly designed and operated filtration plants can clarify water making
disinfection more effective and can remove microorganisms leaving fewer for
the disinfection barrier to inactivate.
It is important to continue waterborne disease surveillance and improve
the reporting of outbreaks so that information will be available on their causes.
To be effective in reducing waterborne disease risks, regulations and
surveillance activities must be based on outbreak experiences.
This is an abstract of a presentation and does not necessarily reflect EPA
policy.
The 1986 SDWA Amendments and Drinking Water Regulations. PAUL S
BERGER (Microbiologist, Office of Drinking Water. US Environmental
Protection Agency. Washington, DC) and STIG E. REGLI (Environmental
Engineer, Office of Drinking Water, US Environmental Protection Agency,
Washington. DC).
The Safe Drinking Water Act Amendments passed by Congress in 1986
require the US Environmental Protection Agency (EPA) to develop drinking
water regulations for 83 contaminants, including total coliforms, turbidity,
heterotrophic bacteria, viruses, Giardia, and Legionella. In response, the
EPA's Office of Drinking Water proposed two regulations on November 3.
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1987: the Total Coliform Rule and She Surface Water Treatment Rule (SWTR).
The proposed total coliform regulation significantly revises the existing
regulation. Coliform limits (maximum contaminant levels or MCLs) have
traditionally been based on density, but in the proposed rule would be based
on the presence or absence of detectable coliforms m a 100-ml sample of
water. The proposal sets limits on the percentage of water samples which
could be coliform-positive, and specifies the minimum monthly monitoring
frequency, required analytical methodology, and the response necessarywhen
a sample is found to be coliform-positive.
The proposed SWTR includes a) criteria under which filtration would be
required and procedures by which the State would determine which systems
must install filtration, and b) disinfection requirements for water systems using
surface water sources. The filtration and disinfection requirements are
designed to protect against the potential adverse health effects of exposure to
Giardia, viruses, Legionella, as well as many other pathogenic organisms.
The SWTR also controls the levels of heterotrophic bacteria and turbidity.
Later. EPA will publish additional regulations requiring groundwater systems to
disinfect their water before distribution to customers and establish criteria by
which a water system could avoid disinfection practice.
Surveillance for Waterborne Illness and Disease Reporting: Federal
Responsibilities and Requirements. ROBERT V. TAUXE, M.D.. M.P.H.
(Enteric Diseases Branch, Division of Bacterial Diseases. Center for Infectious
Diseases. Centers for Disease Control, Atlanta, Georgia.)
Since 1971. the Centers for Disease Control m collaboration with the
Environmental Protection Agency has collected and reported data on
outbreaks of illness associated with water intended for drinking. The purposes
of this surveillance are: 1) to determine trends in the incidence of waterborne
diseases in the United States, 2) to characterize the epidemiology of
waterborne diseases, 3)to disseminate information on waterborne disease, and
4) to provide a basis for evaluating the effect of disease control efforts. For
each outbreak, data are collected on the clinical illness, on the epidemiologic
data which implicated drinking water as the vehicle, and on the results of the
investigation of the water supply system. These data are reported voluntarily
by state agencies on a standard form. Interpretation of these data is limited
by under reporting, and by the differences in interest and resources that state
and local health agencies have for waterborne disease. During the period
1971-1985, there has been a decrease in outbreaks due to the classic
waterborne pathogens hepatitis A, Salmonella typhi, and Shigella; at the same
time Giardia, Cryptosporidium, Campylobacter and the Norwalk agent have
emerged as important waterborne pathogens. In this time span, the most
frequent type of water supply system involved in outbreaks was the
community system; the most frequent identified defect in the water supply
was a deficiency in water treatment. More complete epidemiologic
investigations, advances in laboratory techniques, and standardized reporting
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of waterborne disease outbreaks will augment the national surveillance of
waterborne disease outbreaks.
Epidemiologic Methods for the Investigation of Waterborne Diseases
RICHARD L. VOGT, M.D (State Epidemiologist. Vermont Department of
Health. Burlington).
I.Objectives of a waterborne investigation
A. First: to protect the health of the people at risk by stopping
waterborne spread of the agent
B. Second: to determine the cause of the outbreak
C. Third: to correct existing defects in the water distribution system
D. Fourth: to learn about new aspects of waterborne disease
F. Other
II.Information sources
A. Health care providers
B, Water supply operators
C. Local health departments
D. News media
E. Disease reporting system
F. Other
III. Steps to an investigation
A. Case definition
B. Organization of data
1. Person
2. Place
3. Time
C. Hypothesis test: is water responsible?
D. Epidemic curve
E. Types of study designs
1. Population studies
2. Follow-up studies
a. Random-digit telephone survey
b. Door-to-door household survey
c. Cohort studies
3. .Case-control studies
a. Cases identified in hospitals, doctors' offices, health department
reports
b. Controls selected from similar settings
F. Analysis of data
t. Univariate analyses
a. Cohorts (2x2 tables, attack rates, relative risks)
b. Case-control studies (odds ratios)
c. Household sampling (t-tests, non-parametic analyses)
2. Dose-response relationship
G Other innovative methods
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1. Small cohort study
2. Environmental sample survey
H. Analyses for etiologic agents
1. Bacterial
2. Parasitic
3. Viral
4. Serology studies
I. Investigation caveats
1. Mixed results with special surveillance for outbreaks
2. Exposure information
a. Decay of information over time
b. Water preference data
c. Questionnaire response vs. diary
d. Diarrhea as a confounding factor
3. Evaluation household index cases or early cases in an outbreak if
widespread secondary transmission occurs
4. Difficulty in choosing comparison populations (problems with
confounding)
a. Communities may not be similar in follow-up studies
b. Comparison populations may be dissimilar in case-control
studies
c. Confounding may be evaluated after completion of the study
Principles of Water Filtration. GARY S. LOGSDON (Chief. Microbiological
Treatment Branch, Drinking Water Research Division, Risk Reduction
Engineering Research Laboratory, USEPA, Cincinnati. OH).
Three processes generally used to filter water are diatomaceous earth
(DE) filtration; slow sand filtration; and coagulation, generally in conjunction
with other pretreatment, followed by granular media, rapid rate filtration. DE
filters employ a thin (1/8 inch or greater) layer of fine, porous filtering material
and generally remove particles by the straining mechanism. Slow sand filters
employ a bed of sand about 3 to 4 feet deep, and remove particles by
attachment mechanisms. In addition, larger organisms living in the slow sand
filter bed prey upon smaller organisms. Rapid rate filters employ beds of
media generally 2 to 3 feet deep. A single filtering material sometimes is
used. Often two or three different kinds of media, having different size ranges
and specific gravities, are used. Removal occurs mainly by attachment of
particles to grains of filtering material.
Mechanisms causing particles to attach to grams oi filtering material
include interception, sedimentation, and random (Brownian motion). The
effect of these mechanisms varies with media grain size, particle size, filtration
rate, and some other factors. An especially important factor is the degree of
"stickiness" or instability of colloidal particles. When a colloid touches a gam
of media, it is more likely to stick to the gram if the surface charge of a colloid
is near neutral, rather than highly electronegative or highly electropositive.
Thus pretreatment that accomplishes particle destabilization is very important
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in rapid rate filtration. Cathionic polymers or salts of aluminum or iron are
used to coagulate and destabilize colloids. Biological activity in slow sand
fitters is thought to cause production of excellolular polymers that promote
particle destabilizatton. This paper shows how filter design concepts, such as
media size, bed depth, and filtration rate, are related to filtration principles
Principles of Drinking Water Disinfection for Pathogen Control. JOHN
C. HOFF {Research Microbiologist. Microbiological Treatment Branch.
Drinking Water Research Division, Risk Reduction Engineering Laboratory,
U.S. Environmental Protection Agency, Cincinnati. OH).
The pathogens that must be inactivated by drinking water disinfection
comprise a diverse group of microorganisms (bacteria, viruses, protozoans)
with regard to occurrence, size, mode of existence, and resistance to
disinfectants. Of the many chemical and physical disinfecting agents
available, only a few have been widely applied for large scale drinking water
treatment in the U.S. or other countries. These include free and combined
chlorine, chlorine dioxide and ozone. The kinetic nature of microorganism
inactivation by disinfectants was described many years ago and much
information has been developed on the comparative resistance of
microorganisms and the comparative effectiveness of disinfectants. Only
recently have efforts been made to apply this information to the development
of scientifically based drinking water disinfection requirements. This approach
is based on use of disinfectant concentrations (C) and contact times (t)
required for the inactivation of target pathogens under various conditions of
water pH and temperature. While the effects of temperature increases are
consistent with all disinfectants and pathogens, i.e. inactivation rates increase
as temperature increases, pH effects vary depending on the disinfectant and
target pathogen. The influence of these factors and others including turbidity
and mixing efficiency will be discussed.
This is an abstract of a presentation and does not necessarily reflect EPA
policy.
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Environmental Sampling, Methods, Limitations, and Data Interpretation.
JOAN B. ROSE (Departments of Microbiology and Immunology and Nutrition
and Food Science. University of Arizona. Tucson).
As the role of contaminated water was being elucidated m the
transmission of viruses (enteroviruses, hepatitis A virus. Norwalk virus
rotavirus), parasites (Cryptospondium and G/ardia). and bacteria
(Campylobacter). methods were under development for the detection of these
microorganisms in water. Filtration methods have developed for detectio of
both the viruses and parasites. This includes collection of large volumes of
water (400L) after which the filters are processed and the concentrates
clarified. The samples are assayed on cell culture and using microscopic and
immunofluorescent techniques for viruses and parasites, respectively. For
bacteria such as Campylobacter, filtration methods are also utilized (1L
samples) followed by enrichment and selective culture techniques.
At issue with any of these methodologies is the effect of water quality on
the recovery efficiencies. Other limitations include: 1) lack of cell culture
techniques tor viruses such as the Norwalk virus, 2) inability to assess viability
of the protozoa and 3) the detection of non-cultivatable and stressed bacteria.
In most cases during the investigation of a waterborne outbreak the
etiological agent is not recovered from the suspected water source. This
pattern, however, is gradually changing. Coxsackie B viruses and hepatitis A
virus were iso-tated from an outbreak of gastroenteritis where the hepatitis
infections did not appear in the community until several weeks later. During
one of the largest waterborne outbreaks, caused by Cryptospondium, oocysts
were isolated from drinking water following conventional treatment.
Campylobacter and particularly Giardia. have been detected in the drinking
water during several waterborne outbreaks.
Recommendations for environmental sampling include 1) Immediate
collection of the water samples upon recognition of an outbreak. 2) Collection
of a minimum of 4QOL for viruses and parasites and 11 for bacteria. 3)
Collection of three replicate samples of an individual well or 8 to 10 samples of
the treated water (distribution system and deadend mains). 4) Collection and
assay for a broad range of microorganisms.
Investigation of Outbreaks Emphasizing Engineering/Epidemiology
Interactions. EDWIN C. LIPPY, P.E. (Engineer Director, US Public Health
Service, Retired; Self-employed, Consulting, Cincinnati. OH)
The on-scene investigation and analysis of water systems that were
subjected to waterborne disease outbreaks provided numerous experiences
which are discussed during this presentation. The information developed
during investigations, and proving useful to the engineer and the
epidemiologist, are presented through the use of examples from actual
disease outbreaks
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Epidemiologic Characteristics of Waterborne Cryptosporidiosis.
DENNIS D. JURANEK (Chief. Epidemiology, Parasitic Diseases Branch
Division of Parasitic Diseases. Centers for Disease Control. Atlanta. GA.).
Cryptospondium. an intestinal protozoan parasite transmitted by the iecai-
oral route, is a well-known cause of diarrhea m animals but has been
recognized only recently as a cause of diarrhea in humans. The parasite first
gamed national attention as a cause of severe, incurable diarrhea m patients
with AIDS More recently it has been recognized as important cause of
diarrhea in persons who have no obvious immunodeficiency. Risk factors for
infections include: 1) exposure to stool of infected animals (especially calves).
2} exposure to diaper-aged children who attend day care centers, 3) anal-oral
sexual practices, and 4) drinking contaminated water.
Municipal waterborne outbreaks of Cryptosporidiosis were unrecognized
until 1984 when a sewage-contaminated well was implicated in an outbreak of
diarrhea in Braun Station, Texas. In January of 1987. CDC m collaboration
with the Georgia Department of Human Resources, EPA. and the University of
Arizona had the opportunity to investigate the first waterborne outbreak
involving a surface water supply and a modem water treatment facility that
utilized rapid sand filtration. The investigation revealed that Cryptospondium
oocysts were able to breach the water treatment facility which was in
compliance with EPA and State of Georgia limits for chlorine residual, coliform
bacteria, and turbidity levels. An estimated 13,000 residents (40% of people
drinking municipal water) become ill. The major features that distinguish
Cryptosporidiosis from giardiasis are 1) Cryptospondium's small size (3-4 urn)
which requires better filter performance for removal than for Giardia cysts (8-
12 um). 2) Cryptospondium's high resistance to disinfectants, e.g it can
survive chlorine concentrations of 40,000 mg L or higher. 3) the greater
potential for water contamination by the feces of Cryptospondium infected
animals. 4} Cryptospondium's higher infection rate in the exposed population.
e.g. 40% for Cryptospondium vs. 1% to 10% for Giardia. 5) a higher illness
rate among those infected, e.g. 95% for Cryptospondium vs. < 50°o for
Giardia, and 6) the absence of antiparasitic drugs to treat the Cryp-
tosporidiosis.
Troubleshooting an Existing Treatment Plant. GARY S. LOGSDON
(Drinking Water Research Division, Risk Reduction Engineering Research
Laboratory. USEPA, Cincinnati. OH). LEWIS MASON (Carrollton Water
Treatment Plant. Carrollton, Georgia) and JAMES B. STANLEY. JR. (Keck &
Keck. Atlanta. Georgia).
During January and February. 1987, a waterborne disease outbreak
caused by Cryptospondium occurred in Carrollton, Georgia. Several thousand
persons were estimated to have been ill with gastrointestinal disease at this
time An engineering investigation was carried out at the Carroliton treatment.
plant during the first week of February The paper describes the evaluation
experience and presents the findings ol the filtration plant evaluation
27
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experience and presents the findings of the filtration plant evaluation, the
recommendations made, follow-up actions by the utility, the costs of the
improvements, and the results with respect to turbidity of the filtered water
The 8 MGD Carrollton filtration plant actually consists of two side-by-side
4 MGD conventional treatment trains that are hydrauiically separated Two
banks of five filters each are located in the filter building. The plant can be
operated only at 4 MGD or 8 MGD.
The plant evaluation revealed a temporary absence of mechanical
flocculation. during a changeover from horizontal shaft reel-type floccuiators to
vertical shaft turbine floccuiators. Equipment for monitoring filter behavior was
inadequate or not functional. Filters were sometimes restarted without
backwashmg after being operated and shut off.
At the conclusion of the evaluation, a list of recommendations was
presented. These dealt with raw water, rapid mix, chemical feed, flocculation.
sedimentation, filter operation, filter monitoring, the laboratory, the distribution
system and human resources. These are explained in the paper. Follow-up
actions are also described, and include facilities repair, renovation, and
improvement and operating procedure changes.
The capital improvements, made at a cost of $277.000, have resulted in
production of filtered water turbidity in the range of 0.03 to 0.08 NTU, for a
monthly average. Before the outbreak, the monthly average filtered water
turbidity tor December. 1986, was 0.52 NTU. A substantial improvement has
been attained at a reasonable cost.
This is an abstract of a presentation and does not necessarily reflect EPA
policy.
Chronic Diarrhea in Henderson County, Illinois. JULIE PARSONNET
(Enteric Diseases Branch, Division of Bacterial Diseases, Centers for Disease
Control. Atlanta, GA) and SUSAN TROCK (Division of Field Services.
Epidemiology Program Office, Centers for Disease Control, Springfield. IL).
In July-August 1987, an outbreak of chronic diarrhea affected 72 people in
rural Henderson County, Illinois. Illness was characterized by non-bloody
diarrhea (median 12 stools/day), urgency (100%), fecal incontinence (64°-i)
and weight loss (mean 10 IDS). Nine patients were hospitalized; none died.
There was no clinical improvement with antimicrobial therapy. Small bowel
and colomc biopsies performed on selected patients were not diagnostic. No
bacterial, mycobacterial, viral or parasitic known to be enteropathogenic were
detected in stools.
Case-control studies implicated a restaurant (p = 0.0001) and.
subsequently, the wel! water served in the restaurant (p = 0.04, OR = 9.3) as
the vehicle of transmission. A cohort study of truck drivers who frequented
the restaurant demonstrated a dose-response relationship between water
consumption and development of illness. There were numerous sanitation
violations within the water distribution system which could possibly have
permitted water contamination; however, no pesticides, herbicides, heavy
metals, mycobactena. viruses or parasites were detected in the water.
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This is the first outbreak of chronic diarrhea linked to untreated water A
large outbreak in Brainerd. Minnesota in 1984-1985 resulted from drinking
unpasteunzed milk Reports of continued sporadic cases m the area suggest
a possible endemic focus in the Midwest.
Waterborne Giardiasis in Pittsfield, Massachusetts: Epidemiologic
Perspective. GEORGE P. KENT. M.D. (Department of Medtcme. Stanford
University School of Medicine. San Jose. CA: formerly with the CDC).
in the period November 1, 1985 to January 31. 1986. 703 cases of
giardiasis were reported in Pittsfieid, Massachuselts (population 50.265). The
community obtained its water from two main reservoirs (A and B) and an
auxiliary reservoir (C). Potable water was chlorinated but not filtered. The
incidence of illness peaked approximately two weeks after the city began
obtaining a major portion of its water from reservoir C. which had not been
used for three years. The attack rate of giardiasis for residents of areas
supplied by reservoir C was 14.3''1000, compared with 7.0 1000 in areas that
received no water from reservoir C. A case-control study showed that persons
with giardiasis were more likely to be older and to have drunk more municipal
water than household controls. A community telephone survey indicated that
over 3.800 people could have had diarrhea that might have been caused by
Giardia, and 95 percent of households were either using alternate sources of
drinking water or boiling municipal water. Environmental studies identified
Giardia cysts in the water of reservoir C. Cysts were also detected in the two
other reservoirs supplying the city, but at lower concentrations This
investigation highlights the risk of giardiasis associated with unfiltered surface
water systems.(Abstract excerpted from the article entitled. "Epidemic
Giardiasis Caused by a Contaminated Public Water Supply." GEORGE P
KENT, M.D.. et al. American Journal of Public Health 1988.. 78139-143
reprinted with permission of the American Public Health Association.)
An Outbreak of Ice-related Norwalk Gastroenteritis: Pennsylvania and
Delaware. JAY R. POLINER (Director, Eastern New York Occupational Health
Program), ROBERT CANNON (Medical Epidemiologist. Center for Infectious
Disease. Centers for Disease Control).
Between September 19 and 25, 1987. a series of outbreaks of
gastroenteritis occurred among participants and spectators at an
intercollegiate football game in Philadelphia and a museum fundraiser in
Delaware. A field survey of two of these groups impliated ice consumed m
carbonated and alcoholic beverages (Relative risk = 4.3. with 95°<> confidence
interval of 3.4 to 5.4). Serological testing of students identified Norwalk agent
as the causative agent
The ice. distributed in Pennsylvania. Delaware, and New Jersey, was
traced to a manufacturer in southeastern Pennsylvania whose wells had
flooded following a torrential rainfall on September 8. From the limited ice
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production records available and records of ice consumption by different
groups, we estimated that 5000 cases may have occurred during these
outbreaks.
This is one of the fargest outbreaks of Norwalk gastroenteritis in recent
years. Ice has rarely been implicated in outbreaks of gastroenteritis, and the
investigation and prevention of ice-related outbreaks can be complicated by
lack of labelling and variations in manufacturing Assuring safe watr supplies
for ice manufacturing may prevent further outbreaks.
Waterborne Giardiasis in Pittsfield, Massachusetts: Engineering
Perspective. JOHN J. H1GGINS (Regional Director, Massachusetts
Department of Environmental Quality Engineering, Springfield).
In December of 1985, the Massachusetts Department of Public Health
received reports of a large number of cases of giardiasis in the greater
metropolitan Pittsfield area. State, local, and federal agencies responded and
were able to determine that the outbreak resulted from a unique combination
of construction activities, equipment malfunctions and weather conditions.
Discussed are the series of events that led up to the outbreak, the
investigation which was conducted, and the steps which have been taken to
prevent further occurrences.
Development of Data Collection Instruments: Questionnaires and
Interview Schedules. CHARLOTTE A. COTTRILL (Health Effects Research
Laboratory. EPA, Cincinnati, Ohio).
Information obtained from interviews and self-administered questionnaires.
is key to the investigation of waterborne disease outbreaks. Obtaining
accurate information from interviews with cases and persons at risk is
essential in determining if a water-borne outbreak is occurring and in the
actual investigation of an outbreak. This discussion will attempt to relate
general principles of social/behavioral science and survey research to the
investigation of outbreaks by considering these investigations as continuous
research processes involving two broad stages, the formulation stage and the
research state.
The initial stage is labeled the "formulation" or exploratory stage because
this is when a vaguely defined situation becomes more clearly defined leading
to the decision of whether or not to conduct an investigation. The information
obtained in this stage also provides important background for defining the
problem and developing the research design and the necessary forms.
including questionnaires and interview schedules and guides. Therefore, the
"formulation" stage gives rise to more systematic and rigorous investigation
which this discussion will treat as the second stage.
During the "formulation" stage, it is likely that interviews will be conducted
to obtain more detailed information about the situation. This may require more
flexibility than afforded by a standardized questionnaire. The "focused in
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depth" interview is particularly well-suited to this type of task. Because of its
flexibility, the focused interview can provide more detail than a highly
structured interview because it gives both the interviewer and respondent
more latitude. This method may also be helpful because the respondent may
raise issues and questions that the investigators have not considered or were
awareof.
This discussion will address the development and usage of interview
guides in the formulation stage of a suspected waterborne disease outbreak.
proceeding to the development of structured interview schedules and
questionnaires for usage in the "research or investigation" stage. The latter
part of the discussion focuses on questionnaire construction and question
writing. It attempts to provide a concise overview that includes: (1) choosing
the mode of administration; (2) writing questions; (3) common errors in
question writing; and (4) formal characteristics of questions. The emphasis is
on the development of well designed questionnaires that will contribute to the
collection of accurate and complete information and facilitate data reduction.
analysis, and interpretation.
Data Analysis: Estimating Risk. NEAL D. TRAVEN (Instructor. Department
of Epidemiology, Graduate School of Public Health, University of Pittsburgh.
Pittsburgh PA).
Statistical analysis of questionnaire data collected from persons who may
have been exposed to suspected disease-causing microorganisms is an
essential component of the investigation of waterborne disease outbreaks
This paper reviews some important aspects of epidemiologic data analysis as
they apply to waterborne outbreak investigation.
Among the topics discussed are point estimates of risk (relative risk, odds
ratio, and attack rate), confidence intervals of the risk estimates, and the
interrelationship between sample ssze and statistical power Where
appropriate, illustrative examples are taken from data presented m
investigation reports of actual waterborne disease outbreaks.
One step removed from these statistical'analytic considerations are the
issues of reliability and validity of the information on which the epidemiologic
data analysis is carried out. Data of uncertain reliability, whether due to poorly
designed questionnaires, unclear responses, or myriad other reasons, can bias
the analytic results of an outbreak investigation. The influences of such bias
and non-reliability on risk estimation are discussed.
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Data Interpretation: Differences Between Outbreak Investigation and
Research Epidemiology. NEAL D. TRAVEN (Instructor, Department of
Epidemiology. Graduate School of Public Health, University of Pittsburgh.
Pittsburgh PA).
Much of the early history of epidemiology, such as Snow's work on
cholera, revolved around investigation of outbreaks of acute infectious
diseases. Outbreak investigation of waterborne diseases still owes much to
those methodologies developed in the 19th and early 20th centuries.
Improvements in sanitation and drinking water purification, advances in
microbiologic identification of pathogens, and the wide availability of vaccines.
antibiotics, and medical care have vastly decreased the number and scope of
such outbreaks in industrial and post-industrial societies. Since World War II.
then, the research focus of epidemiologists has turned increasingly to such
chronic conditions as heart disease, cancer, diabetes mellitus, and a host of
others.
In a research environment where Koch's postulates are of diminished
utility, epidemiologic study designs and analytic methodologies have been
developed to examine such multifactorial diseases. Instead of "causes."
epidemiologist now search for "risk factors" of disease. Much attention is paid
to associated diseases, the influence of health behaviors, environmental and
occupational exposures, genetic predisposition, and many other confounding
or interaction factors. Selection of appropriate study subjects is of
overwhelming importance in such research. In addtion, the purview of
epidemiologic methodology has now expanded to include such fields as
controlled clinical trials and evaluation of health programs.
In this paper, these newer epidemiologic methodologies are briefly
contrasted with those of outbreak investigation. Possible avenues for analytic
epidemiologic research in the drinking water field are discussed as well.
Emergency Response and Control Measures. GAYLE J. SMITH (Bureau
of Drinking Water/Sanitation, Utah Department of Health. Salt Lake City).
Effective response and control measures must be both timely and
appropriate. Often attempts at timeliness cloud or minimize considerations of
appropriateness and vice versa. What are the relative trade-offs between
these two considerations? How can these considerations compliment each
other?
Many response options are available for any given emergency. The
available on-hand data may be insufficient to clearly define the most
appropriate responses. Yet, as public health officials, we must take action to
protect the health of our citizens! How much data do we wait for before we
take action? Recognizing that we must frequently act without definitive data,
what actions maximize public health protection and, at the same time,
32
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minimizes public health risk if the cursory diagnosis of the emergency is m
error?
Involvement of the news media and politicians in emergency situations
often necessitates spending scarce resources on non-vital but highly urgent
responses. How does the public official satisfy the urgent, less vital neeas
that cannot be ignored and yet maximize resource dedication to vital public
health protection actions?
Appropriate actions may change as additional data more clearly define the
characteristics of the outbreak emergency. Are public officials always
objective and willing to modify actions to correspond with the dictates of new
data?
The relative success or failure of emergency responses hinge on clear.
concise and appropriate communications! Is there a spokesperson for each
emergency? Does the public know who this person is and how to access
him/her? What communication roles should the State and local health
departments fill to compliment the communications network? Who speaks to
the news media? Who interfaces with the politicians?
The appropriateness of the emergency response and control measures
are extremely important, not only to minimize adverse public health impacts,
but to reinforce in the public (and political) mind the value of a well disciplined
and competent public health team.
Surface Water Source Protection. JOSEPH L. QUICKER (Water Quality
Director, Portland Water Bureau. Portland, OR).
Obtaining the best possible water quality is the goal o1 any surface water
service protection program. Described are the process by which a surface
water source protection program can be developed, the threats that are most
commonly found to water quality in surface supplies, the general means to
control those threats, and some of the upcoming problems and needs in the
field of watershed protection. The City of Portland's Bull Run Watershed is
used to illustrate application of some of these concepts.
Distribution System Protection. PETER C. KARALEKAS, JR. (Chief. Water
Supply Section. U. S. Environmental Protection Agency, Boston, MA).
Sanitary defects in the distribution systems of public water systems have
caused a number of waterborne disease outbreaks. Cross connections.
inadequate disinfection of new water mains, open storage reservoirs, and
corrosion of household plumbing and service lines are among the most
common reasons cited as the cause of distribution system related outbreaks.
There are a number of mechanisms available to regulatory agencies and
public water supply systems to detect and eliminate these deficiencies
Sanitary surveys, regulations, plumbing code enforcement, cross connection
surveys and a more recent innovation, namely, the certification of backflow
33
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prevention device testers can be used to deal with distribution system
problems.
Evaluating Treatment Plants for Particulate Contaminant Removal.
GARY S. LOGSDON (Chief. Microbiological Treatment Branch. Drinking Water
Research Division, Risk Reduction Engineering Research Laboratory.
U.S.E.P.A.. Cincinnati, OH).
Evaluation of water filtration plants is a multi-stage process that should
begin with careful planning. The recommended procedure includes
determining project goals, reviewing available information, and evaluating plant
hydraulics and flow patterns. Processes that should be evaluated include
chemical feed selection and control, rapid mixing, floccuiation, sedimentation
and filtration. Laboratory and pilot facilities should be included in the eval-
uation.
Water filtration must be evaluated in the context of the entire treatment
plant and its operation, because attaining effective pretreatment is essential to
successfully filtering water. The steps listed and described in this paper place
a strong emphasis on the pretreatment processes. No standardized
procedure for chemical dose selection and control exists, so treatment plant
practice is quite variable. Doses may be set by use of jar tests, zeta potential
and streaming current instruments, pilot filters, or by other means. Chemical
feeding practices also vary, and some techniques may be much less efficient
than others. Therefore, a careful evaluation of pretreatment is imperative.
The hydraulics of the treatment plant are important, and strongly influence
performance during floccuiation and sedimentation. Here the uniform
distribution of flow is important, and plug flow is very desirable.
Filter operation should be evaluated to determine if the most appropriate
procedures are being followed. Frequent and sudden rate changes and restart
of dirty filters without backwashing should be avoided because of the
deleterious effects these actions have on filtered water quality. The filtration
process should be carefully monitored in order for the operator to be in control
at all times. The quality of laboratory data and the ways in which operating
data are used to manage the filtration plant should be reviewed.
This paper concludes with some examples of plant improvements.
This is an abstract of a presentation and does not necessarily reflect EPA
policy.
Evaluation of Disinfection Processes and Facilities. GARY S. LOGSDON
(Chief, Microbiological Treatment Branch, Drinking Water Research Division,
Risk Reduction Engineering Research Laboratory, USEPA, Cincinnati. OH).
Evaluation of disinfection is a key aspect of water treatment plant
evaluation during an outbreak. This work could be accomplished in four
phases, including review of plant records, evaluation of disinfection equipment.
34
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inspection of physical processes, and review of chemical monitoring and
quality control as related to disinfection.
Review of operating records can be a useful way to gain an understanding
of water utility practice. The data on chemical purchases should be consistent
with data on water production and chemical dosage. Plant records also should
indicate the extent to which disinfectant residual is carefully controlled or
allowed to fluctuate. With adequate data, the engineer reviewing the facility
may be able to gain an understanding about the disinfectant demand of the
raw water.
An evaluation ol equipment should be undertaken to develop information
on the state of repair of the equipment and on availability of back-up
equipment. Chlorine feed may be adjusted manually, paced with flow.
adjusted based on residual, or based on both flow and residual. The extent of
monitoring equipment should be noted, as well as the availability of a back-up
power supply, especially for systems in which water flows to distribution by
gravity.
Physical processes are important. For free chlorine, chloramine. and
chlorine dioxide, the disinfectant chemical should be dispersed as thoroughly
and instantaneously as possible into the water. After the initial mixing of
chemical disinfectant and water, a period of contact time should be attained.
For the above-mentioned chemical agents uniform contact time for all water
treated is best achieved in plug flow, either in a transmission main or in a
serpentine contact basin. Rate of flow influences residence time, so flow
metering capability is needed. Except for long pipe-lines, contact time is best
determined by conduction tracer studies.
Quality control of all chemical measurements is important Good
laboratory QAQC procedures should be followed when disinfectant doses and
disinfectant residual measurement is not always easy or straightforward The
advice of a chemist on exactly what analytical procedures are appropriate ioi
specific circumstances may be needed.
Disinfection needs to be evaluated carefully, because it is an important
process in water treatment. Merely adding some disinfectant chemical to a
water dose not necessarily render it potable. Each of the aspects of
disinfection mentioned in this paper is important and should be given a careful
and thorough evaluation.
This is an abstract of a presentation and does not necessarily reflect EPA
policy.
Determination of Ct Values. ROBERT M. CLARK (Director, Drinking Water
Research Division, Risk Reduction Engineering Laboratory. U.S.
Environmental Protection Agency, Cincinnati, Ohio).
The Amendment, to the Safe Drinking Water Act require that EPA
promulgate primary drinking water regulations (a) specifying criteria under
which filtration would be required,
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lamblia, viruses, Legionella. heterotrophic plate count bacteria, and turbidity.
If a utility, in addition to meeting other requirements, can demonstrate that
through effective disinfection, it can reduce Giardia levels by 99.9%. then it
will be exempted from the surface water filtration requirement.
To demonstrate that the system ts achieving a specified percent
inactivation, the system would monitor disinfectant residual(s), disinfectant
contact time(s), pH, and water temperature, and apply their data to determine
if the Ct [the product of disinfectant concentration (mg.L) and disinfectant
contact time (minutes) value equafs or exceeds CT values specified in the Sur-
face Water Treatment Rule {SWTR). Ct values necessary to achieve 99.9
percent inactivation of Giardia cysts -by various disinfectants and under
various conditions are specified in EPA's proposed Surface Water Treatment
Rule and Ct values recommended for filtered systems, depending upon the
appropriate level of inactivation, will be specified in the SWTR Guidance
Manual. Therefore, understanding Ct values and their significance is critical to
understanding the SWTR. The Ct concept is based on an empirical equation
stemming from the early work of Watson and is expressed as:
K = C"t (1)
where K = constant for a specific microorganism exposed under
specific conditions.
C = disinfectant concentration in mg'l
n = constant, also called the "coefficient of dilution"
t = the contact time, required for a fixed percent inactivation in
minutes.
For purposes of this paper the discussion will focus on chlorine
disinfection. The destruction of pathogens by chlorination is dependent of a
number of factors, including water temperature, pH. disinfectant contact time,
degree of mixing, presence of interfering substances (which may be related to
turbidity), and concentration of available chlorine. In order to account for these
data a regression model that explicitly incorporates the variables of
concentration, pH and temperature was developed. This model is as follows:
t = RC*pHbtempc (2)
t = time to a given level of inactivation in minutes
C = concentration of disinfectant in mg/L
pH = pH at which experiment was conducted
temp = temperature at which experiment was conducted in °C
36
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To provide the Ct. value equation (2) was multiplied by C yielding the
following "Ct" equation:
Ct = RC
For the original Ct calculations Equation (3) was applied to animal
mfectivity experiments conducted by Dr. Charles Hibler.
These experiments provided Ct values at 99.99°'o mactivatron. The
equation derived was as follows:
Ct = 0.985C°176 PH2752 temp-'"7 (4)
Equation (4) was used as the basis for calculating Ct values in the SWTR.
The weakness of this approach is that the calculated Cts are for one level of
inactivation (99.99%). Therefore first order kinetics were assumed to
extrapolate to lower levels of inactivation. In order to provide conservative
estimates for Ct values a 1 log safety factor was used. That is. it was
assumed for purposes of the SWTR that 99.99% inactivation Ct values would
be used as the 99.9% inactivation Ct levels. A more desireable approach
would be to use actual data to calculate Ct values at lower levels of
inactivation.
Therefore, an attempt was made to find other data sets that would be
consistent with the Hibler data but would provide data at lower levels of
inactivation. Statistical tests were utilized to determine that a data set
developed by Jarroll was consistent with the Hibler data. A new equation was
developed based on the Hibler- Jarroll data as follows:
Ct = 0.12 I -027 C° '9 pH25->6temp-015(5)
where R. C, pH. ternp, a,b,& c are previously defined, and
I = (nactivation ratio (I0'lt; I0 = initial number of organisms and
I, = organisms remaining at time t)
These equations based on Hibler data alone and the equation based on Hibler-
Jarroll data were shown to be compatible at the 99.99% inactivation level
(Table 1). But as shown in Table 1 the 95% confidence values for Cts at
99.9% inactivation using the Hibler-Jarroll data are lower than the 99.9°<>
(actually 99.99%) inactivation levels using the original Hibler data.
This is an abstract of a proposed presentation and does not necessarily
reflect EPA policy.
37
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Table 1. Comparison of Hibler Versus Hibler/Jarroll Estimates (at 5*C)
Hsber Hibler/Jarroll at 99.9%
(mg/L)
0.4
2.0
0.4
2.0
0.4
2.0
Cone.
pH
6
6
7
7
&
8
Estimate
(mean
Ct)
92
122
140
186
202
269
Lower
95%
37.9
58.0
59.1
90.8
83.2
124.1
Mean
51.1
68.9
76.6
103.3
108.8
146.7
Upper
95%
69.0
81.9
99.3
117.5
142.1
173.5
Hibler/Jarroll
at 99.99°M>
(Mean Ct)
91.6
123.6
137.4
185.3
195.1
263.1
Distribution Systems: Treated Water Quality versus Conform Non-
Compllance Problems. DONALD J. REASONER (Research Microbiologist,
Drinking Water Research Division, Risk Reduction Engineering Laboratory.
USEPA, Cincin-nati. Ohio) and EDWIN E. GELDREICH (Senior Research
Microbiologist. Drinking Water Research Division. Risk Reduction Engineering
Laboratory. USEPA, Cincinnati. Ohio).
The overall quality of treated drinking water is subject to deterioration
during distribution. Factors that effect the rate and degree of deterioration
include source water characteristics and quality, type of treatment and
treatment effectiveness, disinfectant residual, temperature. pH, flow rate.
residence time, organic carbon available for microbial growth, the numbers
and types of microorganisms present, and distribution system age and
condition. The bacterial load of the distribution water is significantly
influenced by several of these (actors.
The occurrence of coliform bacteria, used as indicators of treatment
effectiveness and sanitary quality, in treated distribution water is cause for
concern because of the possibility that disease causing organisms may also
be present. Coiiform occurrences may cause the utility to be out-of-
compliance with the coliform MCL of the Primary Drinking Water Standards.
Thus, conditions that favor coliform persistence or growth within a distri-
bution system impact our ability to discriminate between those situations in
which there really is adverse health risk and those in which there is only an
apparent adverse health risk.
During the past few years, documentation of intermittent and^or persistent
coliform occurrence problems in a number of water distribution systems,
primarily in the Eastern half of the United States, has stimulated interest and
38
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concern about this problem. This information suggests that there are
conditions under which coliform survive, or may actively grow, m biofilms that
develop on the pipe surfaces and sediments in the distribution system. While
our knowledge of the specific conditions thai permit coliform
persistence/colonization m distribution systems is incomplete, educated
guesses can be made that will help m formulatmgpractical approaches so
remediation and control of colitorm noncomphance problems. Continuing
research into the underlying causes of coliform persistence colonization m
distribution systems is needed so that we will not have to rely on educated
guesses, but operate on firm knowledge.
Discussed are microbiological growth and biofilm formation in drinking
water distribution systems, provides real world examples of coliform
persistence problems, and addresses approaches that have been used to
solve coliform noncompliance problems.
This is an abstract of a presentation and does not necessarily reflect EPA
policy.
Predicting Exposure to Water Contaminants in Distribution Systems.
ROBERT M. CLARK (Director, Drinking Water Research Division. Risk
Reduction Engineering Laboratory, U.S. Environmental Protection Agency.
Cincinnati, Ohio 45268).
The Safe Drinking Water Act (SDWA) of 1974 requires that the United
States Environmental Protection Agency establish maximum contaminant level
goals (MCLGs) for each contaminant which may have an adverse effect on the
health of persons. Each goal is required to be set at a level at which no known
or anticipated adverse effects on health occur, allowing for an adequate
margin of safety. Maximum contaminant levels (MCLs) must be set as near to
MCLGs as feasible. Although the SDWA has been interpreted as meaning
that MCLs shall be met at the consumers tap, most regulatory concern has
been focused on water quality as it leaves the treatment plant before entering
the distribution system. The SDWA regulations that emphasize system
sampling are those that deal with microbiological contamination and total
trihalomethanes. However, interest is growing in acquiring an understanding
of variations in water quality that are found in drinking water distribution
systems. Acquiring such art understanding and then predicting the
propagation and distribution of water networks requires insight into the kinetics
of formation of chemical and biological substances as well as the hydraulics of
mixing and transport. The Drinking Water Research Division of EPA has
developed several models for predicting exposure to contaminants in drinking
water distribution systems. These models include a steady state model; a
sequential steady state modei: a contaminant propagation model; a time of
travel model; and, a dynamic water quality algorithm.
These models were developed within the context of a cooperative
agreement between the North Penn Water Authority. Lansdale. PA (NPWA)
and the EPA's Drinking Water Research Division The NPWA serves 14.500
39
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customers in 10 municipalities with an average of 5 million gallons of water per
day (MGD). Water sources include 1 mgd treated water purchased from the
Keystone Water Company which is a surface source and 4 mgd from 40 wells
operated by NPWA. There are distinct chemical characteristics associated
with Keystone water compared with well waters. Keystone water contains total
trihalomethane (TTHM) at significantly higher levels then the well water. Well
water contains volatile orgamcs and inorganic chemicals. The TTHMs in the
Keystone water were assumed to be at steady state and were used as a
tracer. A major first step in the project was to hydraulically model the
distribution system in a network represented by 528 links and 456 nodes. The
network hydraulic model used was the WADISO Model, developed by the U.S
Army Corps ol Engineers. It contains provisions for both steady state and
quasidynamic hydraulic modeling (extended period simulation). Hydraulic
information from selected scenarios was inserted into the Water Supply
Simulation Model (WSSM) developed by EPA's Drinking Water Research
Division. WSSM utilizes the SOLVER algorithm based on a series of
simultaneous equations describing water quality at each node to determine the
steady state concentration throughout the network.
These models were used to accurately predict historical TTHM levels in
the NPWA system. From this analysis it was clear that some points in the
system could exhibit wide variations in water quality data and a study was
initiated at 6 locations in the system to collect water quality data over 36
hours These data were then used to develop and validate the remaining
models.
The sequential steady state model provided excellent representation of
water quality variations in the system: The contaminant propagation model
illustrated that even though two sources are located far apart, there are
portions of the system that can receive flow from both sources. Average travel
time between various sources and demand points was calculated.
The dynamic water quality model requires much more extensive data
input than the other models as shown in Table 1.
Table 1. Information required by the dynamic water quality model
General Information
• t Time Step
General Network Information:
• Node numbers associated with the end of each Link
• Link lengths
• Pipe diameters
• Node number associated with each source
* Node number associated with each tank
• Tank geometry
initial Conditions:
• Concentration at each node at the start of simulation
• Volume in tank at start of simulation
40
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Information Required (or Each Period:
* Direction and flow m each link
• Velocity m each link (optionally may be calculated based on
pipe diameter)
• Concentration in source flow
However, despite these complexities the dynamic model provided
excellent representation of water quality variations in the system
It was concluded that the steady state model can provide insight into
overall water quality variations and patterns within a distribution system.
interpretation of predictive modeling results must be made in light of an
appreciation of the hydraulics of the system, in particular an understanding of
the flow patterns and directions that create gradients of concentration. Quality
modeling is based on hydraulic modeling, and is highly sensitive to hydraulic
modeling assumptions and results. Field quality data is important in
developing, verifying and understanding predictive models. Such quality data
should be available on a time interval sufficient to reflect daily changes m
system dynamics. Having the tools to predict time-of-travel between points
from any source will allow for realistic water quality monitoring strategies and
to predict exposure from contaminants.
This is an abstract of a proposed presentation and does not necessarily
reflect EPA policy.
Laboratory Support for Clinical Samples: Bacterial. JULIE PARSONNET
(Enteric Diseases Branch, Division of Bacterial Diseases. Centers for Disease
Conlrof. Atlanta. GA).
In the evaluation of an outbreak, isolation of organisms m human
specimens is essential in determining an etiologic agent. If a new agent is
sought, the agent must be found in case specimens but not in those of
controls. The presence of a known pathogen in a vehicle of transmission
provides circumstantial evidence of causation but, with rare exceptions, it is
not sufficient to establish a definitive diagnosis.
Human specimens are commonly analyzed using three techniques:
bacterial culture often in conjunction with tests for epidemiologic markers (e.g..
serotype. antibiotic sensitivity profile or plasmid profile), pathogenioty assays
(e.g., toxin assays or molecular probes for bacterium-specific genes), and
seroiogic tests of blood specimens for anti-bacterial antibodies. One or all of
these methods may be applied to specimens from any given outbreak. New
techniques such as gene amplification may further expand diagnostic
capabilities.
The increasing armamentarium of diagnostic tools for detection ot
bacterial pathogens is likely to result in the discovery of new agents
However, expense and technical requisites presently limit use ol some
techniques to the research setting
41
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Analysis of Water Samples for Bacterial Pathogens. GERARD N.
STELMA JR. (US Environmental Protection Agency, Cincinnati. OH)
Bacteria associated with waterborne illness commonly fall into two
categories, enteric pathogens of fecal origin, and opportunistic pathogens.
which may be indigenous to drinking water distribution systems. The
fastidious nutrient requirements of most pathogens and the high densities of
natural flora which compete for nutrients makes the isolation of these
organisms from drinking water very difficult. Isolation of the enteric pathogens
is further complicated by their low numbers and transient nature in drinking
water. The methods used for isolation and identification of these organisms
from potable water generally are modifications of those developed for clinical
specimens, with concentration and/or enrichment steps incorporated into the
procedure. Frequently, pathogens cannot be isolated, and investigators must
rely on the isolation of indicator organisms of fecal origin, which are present in
higher numbers in polluted waters. Recommended procedures for the
isolation and identification of specific waterborne pathogens and indicators will
be summarized.
This is an abstract of a presentation and does not necessarily reflect EPA
policy.
Virological Analysis of Environmental Water Samples. CHRISTON J.
HURST (Microbiologist, United States Environmental Protection Agency,
Cincinnati. Ohio).
Human enteric viruses can be found in groundwaters and surface waters
within the United States and other countries. Such viruses are capable of
persisting through the various stages of standard drinking water treatment
processes. The different enteric viruses groups will be briefly described. A
summary description is given of the methods that are currently used for
concentrating viruses from water samples and performing virofogical analysis
on the resulting concentrates.
This is an abstract of the proposed presentation and does not necessarily
reflect EPA policy.
Analysis of Water Samples for Protozoa. JAN I. SYKORA (Associate
Professor, Graduate School of Public Health. University of Pittsburgh.
Pittsburgh, PA 15261).
Laboratory analysis of environmental samples for protozoans requires
special techniques dealing with concentration and isolation of individual
agents. Concentration techniques involve various types of filtration,
centrifugation. sedimentation and flotation. Isolation requires cultivation of
protozoans on special media or direct count of protozoan in concentrated
samples using direct staining or immunofluorescent techniques.
42
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Membrane filtration is used to concentrate relatively dense populations of
agents such as free living amoebae, while high volume cartridge filters are
used for separation of protozoans present in low concentration (e.g Giardia.
Crypiospondium).
Isolation of free living amoebae is accomplished by cultivation on
nonnutnent agar seeded with bacteria. Giardta and Cryptospondium counts
are performed by direct microscopic examination of concentrated samples
Our research focused on recovery of Giardia in environmental samples
affected by temperature (water density) and suspended solids. A series of
quality control tests performed on a variety of environmental samples
indicated that cyst recovery is low in samples contaminated by elevated
concentrations of suspended solids. In addition, standard sedimentation at low
temperatures affects isolation of the cyst.
However, in spite of these and other deficiencies the current Giardia
isolation technique proved to be successful in monitoring this agent and thus
preventing additional waterborne outbreaks in the system studied.
43
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APPENDIX C
LISTING OF PARTICIPANTS
44
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Listing of Speakers and Panel Members
Paul S. Berger. PhD.
Microbiologist
Office of Drinking Water
U.S. Environmental Protection
Agency
401 M Street, S.W.. Room EB55D
Washington, DC 20460
(202) 382-3039
Mr. Stuart P. Castle
Drinking Water Section
New Mexico Environmental
Improvement Division
P.O. Box 968
Santa Fe, NM 87501
(505) 827-2778
Robert M. Clark, PhD.
Drinking Water Research
Division
Water Engineering Research
Laboratory
U.S. Environmental Protection
Agency
26 W. Martin Luther King Dr.
Cincinnati, OH 45268
{513)569-7201
Charlotte A. Cottrill, PhD.
A.W. Breidenbach Environmental
Research Center
U.S. Environmental Protection
Agency
26 W. Martin Luther King Dr.
Cincinnati, OH 45268
(513) 569-7221
Mr. Gunther F. Craun
Health Effects Research
Laboratory
U.S. Environmental Protection
Agency
26 W Martin Luther King Or
Cincinnati. OH 45268
(513) 569-7422
Lawrence R. Foster, M.D.
State Epidemiologist
Oregon Health Division
1400S.W. 5th Avenue
Portland. OR 97201
(503) 229-5792
Dr. Charles W. LeBaron
Medical Epidemiologist, Viral
Gastroenteritis Unit
Centers for Disease Control
Atlanta, GA 30333
(404) 639-2395
Mr. Joseph L. Glicker
Water Quality Director
Portland Water Bureau
1120S.W. 5th Avenue
Portland, OR 97204
(503) 796-7471
Mr. John J. Higgins
Regional Director
Massachusetts Department of
Environmental Quality
Engineering
436 Owight Street
Springfield, MA 01103
(413)784-1100
John C. Hoff. PhD.
Risk Reduction Engineering
Laboratory
Drinking Water Research
Division
U.S. Environmental Protection
Agency
26 W. Martin Luther King Dr.
Cincinnati, OH 45268
(513)569-7331
45
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Dr. Christon J. Hurst
Health Effects Research
Laboratory
U.S. Environmental Protection
Agency
26 W. Martin Luther King Dr.
Cincinnati, OH 45268
(513) 569-7461
Dr. Gary L. Logsdon
Chief, Microbiological
Treatment Branch
Drinking Water Research
Division U.S Environmental Protection
Agency
26 W. Martin Luther King Dr.
4526Cmcmnati. OH
(513)569-7345
Dennis D. Juranek, D.V.M.
Chief, Epidemiology
Parasitic Diseases Branch, CID
Centers for Disease Control
(F-09)
2600 Clifton Road
Building 23/Chambtee
Atlanta, GA 30333
(404) 488-4435
Mr. Peter C. Karalekas, Jr.
Chief, Water Supply Section
U.S. Environmental Protection
Agency
Region 1
John F. Kennedy Building
Boston. MA 02203
(617)565-3655
Mr. Richard J. Karlin
Director, Research Management
Division
AWWA Research Foundation
6666 West Quincy Avenue
Denver, CO 80235
(303) 794-7711
Dr. George P. Kent
Assistant Clinical Professor
Department of Medicine
Stanford University School
of Medicine
25 North 14th Street, #1060
San Jose. CA95112
(408) 977-4507
Ms. Janet L. McGoldrick
Deputy Director
Association of State Drinking
Water Administrators
1911 N. Fort Myer Drive
Arlington, VA 22209
(703) 524-2428
Patricia A, Murphy, PhD.
Toxicology & Microbiology
Division
Health Effects Research
Laboratory
U.S. Environmental Protection
Agency
26 W. Martin Luther King Dr.
Cincinnati, OH 45268
(513)569-7226
Julie Pa;sonnet, M.D.
Enteric Diseases Branch
Division of Bacterial Diseases
Centers for Disease Control
(C-09)
1600 Clifton Road
Atlanta. GA 30333
(404) 639-3753
Jay R. Poliner, M.D.
Director. Eastern New York
Occupational Health Program
1201 Troy-Schenectady Road
Latham. NY 12110
(518)783-1518
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Mr. Edwin C. Lippy
109 West Concord Drive
Lebanon. OH 45036
(513)932-7842
Donald J. Reasoner. PhD
Drinking Water Research
Division
Risk Reduction Engineering
Laboratory
U.S. Environmental Protection
Agency
26 W. Martin Luther King Dr.
Cincinnati, OH 45268
(513) 569-7234
Mr. Stig 6. Regli
Criteria and Standards
Division
Office of Drinking Water
U.S. Environmental Protection
Agency
401 M Street. S.W.
Washington. DC 20460
(202) 382-7575
Joan B. Rose. PhD
Associate/Lecturer
University of Arizona
PHM Bldg. 90, Room 201
Tucson, AZ 85721
(602)621-6982
Frank W. Schaefer, III, PhD
Parasitology and Immunology
Branch
Environmental Monitoring
Systems Laboratory
U.S. Environmental Protection
Agency
26 W. Martin Luther King Dr.
Cincinnati. OH 45268
(513)569-7222
Gerard N. Stelma. PhD
U.S. Environmental Protectton
Agency
Environmental Monitoring
Support Lab.
Division of Microbiology
Bacteriology Branch
26 W. Martin Luther King Dr.
Cincinnati, OH 45268
(513)569-7384
Jan L. Sykora, PhD
Associate Professor
Graduate School of Public
Health
University of Pittsburgh
Pittsburgh. PA 15261
(412)624-3516
Robert V. Tauxe, M.D.
Chief. Epidemiology Section
Division of Bacterial Diseases
Centers for Disease Control
1600 Clifton Road
Atlanta, GA 30333
(404) 639-3753
Neal D. Traven, PhD
Department of Epidemiology
Graduate School of Public
Health
University of Pittsburgh
A436 Crabtree Hall
Pittsburgh, PA 15261
Mr. Jay Vasconcelos
Regional Microbiologist
U.S. Environmental Protectton
Agency
Region 10, ESD, Manchester
Environmental Laboratory
P.O. Box 549
Manchester, WA 98353
(206)442-0370
47
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Mr. Gayle J. Smith
Bureau of Drinking Water.
Sanitation
Utah Department of Health
P.O. Box 16690
Salt Lake City. UT 84116-0690
(801)538-6163
Richard L. Vogt, M.D.
Council of State and
Territorial Epidemiologists
Vermont Department of Health
P.O. Box 70
Burlington, VT 05401
(802) 863-7240
List of Attendees
Ms. Alicia Aalto
U.S. Environmental Protection
Agency
Region 8 (8WMDW)
999 18th Street
Denver, CO 80202-2405
(303)293-1413
Ms. Melanie Abell
U.S. Environmental Protection
Agency
Region 8 (8WMDW)
999 18th Street
Denver, CO 80202-2405
(303)293-1413
Mr. Keith Allen
Mississippi State Department
of Health
Division of Water Supply
P.O. Box 1700
Jackson, MS 39215-1700
<60t) 960-7518
Mr. Marc R. Alston
U.S. Environmental Protection
Agency
Region 8 (8WMOW)
999 18th Street
Denver, CO 80202-2405
(303)294-1424
Mr. Dennis J. Ait
Iowa Department of Natural
Resources
8900 East Grand Street
Des Momes. IA 50319
(515)281-8998
Dr. John S. Andrews
Centers for Disease Control
Maiistop F28
1600 Clifton Road
Atlanta, GA 30333
(404) 488-4682
Mr. Thomas E. Arizumi
Drinking Water Program
Hawaii Department of Health
645 Halekauwila Street
1 st Floor
Honolulu, HI 96813
(808) 548-2235
Mr. Anthony E. Bennett
Texas Department of Health
1100 West 49th Street
Austin, TX 78756
(512)458-7497
Dr. Robert W. Benson
U.S. Environmental Protection
Agency
Region 8 (8WMDW)
999 18th Street
Denver. CO 80202-2405
(303)293-1413999
Mr. Dennis A. Berry
Arkansas Department of Health
4815 West Markham
Little Rock. AR 72205
(501)661-2143
48
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Mr. Chel E Anderson
State of California Department
o! Health Services
1836 S. Commercenter Circle
San Bernadmo. CA 92048
(714)383-4328
Dr Gus Birkhead
New York State Department
of Health
Tower Building. Room 651
Empire State Plaza
Albany, NY 12237
(518)473-4436
Mr. Glenn A. Bodnar
Colorado Department of Health
Drinking Water Program
4210 E. 1 Hh Avenue. Room 300
Denver. CO 80220
(303)331-4548
Ms Pamela A Bonrud
South Dakota Department
of Health
523 East Capitol
Pierre. SD 57501
(605) 773-3364
Mr. David J. Borgeson
Hawaii Department of Health
Hazardous Evaluation and
Emergency Response Program
P.O. Box 3378
Honolulu. HI 96801-9984
(808) 548-2235
Mt. Kenneth H. Bousfield
Utah Bureau of Drinking Water
P.O Box 16690
Salt Lake City, UT 84116-0690
(801)538-6159
Mr. Jerry C. Biberstme
Colorado Department of Health
4210 E. 11th Avenue
Denver. CO 80220
(303). 331-4546
Mr. Michael E. Burke
New York State Department
of Health
2 University Plaza, Room 406
Albany. NY 12203
(518)458-6731
Dr. Ronald L Cada
Colorado Department of Health
4210 E. 11th Avenue
Denver, CO 80220
(303)331-4700
Dr. Robert A. Calder
Florida Department of Health
and Rehabilitative Services
1317 Wmewood Boulevard
Building 5. Room 455
Tallahassee. FL 32399-0700
(904) 488-2905
Mr. Kenneth C. Choquette
Iowa Department of Public
Health
Division of Disease Prevention
Lucas State Office Building
Des Moines. IA 50319
(515)281-8220
Dr. Virginia M. Dato
New Jersey State Department
of Health
Division of Epidemiology
CN-369
Quaker Bridge Office
Trenton. NJ 0826-0360
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Mr. Stuart F. Bruny
Ohio Environmental Protection
Agency
Division of Public Drinking
Water
P.O. Box 1049
1800 Watermark Drive
Columbus. OH 43266-0149
(614)481-7025
Dr. Debra L. Brus
Nevada State Health Division
505 E. King Street. Room 201
Carson City. NV 89710
(702) 885-4740
Dr. Denny H. Donnell, Jr.
Missouri Department of Health
Section of Disease Prevention
1730 East Elm Street
Jefferson City. MO 65101
(314)751-6128
Dr. Millicent Eidson
New Mexico Department of
Health and Environment
Office of Epidemiology
Santa Fe. NM 87503
(505) 827-0006
Mr. Gary L. Englund
Minnesota Department of Health
P.O. Box 9441
Minneapolis, MN 55440
(612) 623-5227
Mr. Jeffrey A. Fontaine
Nevada State Division
o! Health
505 East King Street, Room 103
Carson City, NV 89710
(702) 885-4750
Mr William H Davis
U.S. Environmental Protection
Agency
Region VI
1445 Rose Avenue
Dallas. TX 75202
(214)655-7155
Ms. Charlene Denys
Alaska Department of
Environmental Conservation
P.O. Box 0
Juneau, AK 99811
(907) 465-2653
Mr. Barker G. Hamill
New Jersey Department of
Environmental Protection
Bureau of Safe Drinking Water
Division of Water Resources
401 E. State Street
Trenton, NJ 08625
(609) 984-7945
Dr. Robert H. Hamm
Indiana State Board of Health
1330 West Michigan Street
P.O. Box 1964
Indianapolis, IN 46206
(317)633-8416
Mr. Allen R. Hammer
Virginia Department of Health
109 Governor Street, Room 924
Richmond, VA 23219
(804) 786-1766
Mr. Robert Hart
Arkansas Department of Health
4815 West Markham
Little Rock, AR 72205-3867
(501)661-2623
50
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Mr. Robert M. Gallegos
New Mexico Environmental
Improvement Division
Drinking Water Section
1190 St. Francis Drive
Santa Fe. MM 87503
(505) 827-2782
Ms. Judith Gedrose
Montana Department of Health
and Environmental Sciences
Cogswell Building
Helena, MT 59620
(406) 444-4740
Dr. Kathleen Gensheimer
Maine Bureau of Health
State House. Station 11
Augusta. ME 04333
(207) 289-3591
Mr Richard B Howell
Delaware Division of Public
Health
Silver Lake Plaza
P O. Box 637
Dover. DE 19903
(302) 736-4731
Ms. Vickie D. Hundley
Ohio Department of Health
1372-D West 7th Avenue
Columbus. OH 43212
(614)466-5330
Mr Ray Jarema
Connecticut Department of
Health Services
150 Washington Street
Hartford. CT 06106
(203)566-1253
Mr. Jim W Haynes
Tennessee Department of Health
and Environment
150 9th Avenue. North
Terra Building
Nashville. TN 37219-5404
(615)741-6636
Mr. Craig W. Hedberg
Minnesota Department of Health
717 SE Delaware Avenue
Minneapolis. MN 55440
(612)623-5414
Ms. Donna G. Howell
Montana Water Quality Bureau
Cogswell Building. Room A-206
Helena. MT 59620
(406) 444-2406
Mr. Ron Solberg
North Dakota State Department
o! Health and Consolidated
Laboratories
1200 Missouri Avenue
P.O. Box 5520
Bismark. ND 58502-5520
(701)224-4598
Mr. Kent Kimes
Florida Department of
Environmental Regulation
2600 Blair Stone Road
Tallahassee. FL 32399-2400
(904) 487-1262
Mr. Michael P. Kovach
Michigan Department of Health
3423 North Logan Street
P.O Box 30195
Lansing. Ml 48909
(517)335-8325
51
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Ms. Sue Anne Jenkerson
Alaska Department of Health
and Social Services
3601 C Street. Suite 540
P.O. Box 240249
Anchorage, AK 99524-0249
(907)561-4406
Dr. Suzanne R. Jenkins
Virginia Department of Health
Office of Epidemiology
Madison Building, Room 701
109 Governor Street
Richmond, VA23219
(804) 786-6261
Dr. Mark B. Johnson
Wyoming State Department of
Health and Social Services
479 Hathaway Building
Cheyenne, WY 82002
(307) 777-6004
Mr Glenn Y. Kataoka
Colorado Department of Health
4210 E. 1tth Avenue
Denver, CO 80220
Ms. Lore E. Lee
Arizona Department of Health
Division of Disease Prevention
3008 North Third Street
tPhoenix. AZ85012
(602) 392-4002
Mr. Kirk M. Leitheit
Ohio Environmental Protection
Agency
Division of Public Drinking
Water
P.O. Box 1049
1800 Watermark Drive
Columbus. OH 43266-0149
(614)644-2752
Ms Sandra J Knetzman
New Jersey Department of
Environmental Protection
Bureau of Safe Drinking Water
Division of Water Resources
P.O. Box CN-029
Trenton. NJ 08625
(609) 292-5550
Mr. Robert M. Kriil
Vice President, ASDWA and
Wisconsin Department of
Natural Resources
P.O. Box 7921
Madison, Wl 53713
(608) 267-7651
Ms. Kathy L. Kringiie
Oklahoma State Department
of Health
1000 Northeast 10th Street
Oklahoma City. OK 73152
(405)271-4060
Mr. Donald A. Kuntz
West Virginia Drinking Water
Administration
1800 Washington Street, East
Charleston, WV 25305
(304) 348-2981
Mr. Ronald W. McDougal
Maine Department of Human
Services
Division of Health Engineering
157 Capitol Street
State House, Station 10
Augusta, ME 04333
(207) 289-3826
Dr. Louise M. McFarland
Louisiana State Department
of Health and Hospitals
P O. Box 60630
New Orleans. LA 70160
(504) 568-5005
52
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Mr. Sam W. Lester
Kentucky NREPC
Division of Water
18 Reilly Road
Frankfort Office Park
Frankfort. KY 40601
(502) 564-3410
Mr. Emerson S. Lomaquahu
U.S. Environmental Protection
Agency
Region 8 (8WMDW)
999 18th Street
Denver, CO 80202-2405
(303)293-1413
Mr. Bernard D. Lucey
New Hampshire Department
of Environmental Services
P.O. Box 95
Concord. NH 03301
(603)271-3139
Mr. Frederick A. Marrocco
President. ASDWA and
Pennsylvania Department
ol Environmental Resources
P.O. Box 2357
Harrisburg, PA 17120
(717)787-9035
Ms. Barbara Mazur
Missouri Department of
Natural Resources
P.O. Box 176
Jeflerson City. MO 65102
(314)751-5331
Mr. Craig R. Nichols
Utah Department of Health
P.O Box 16660
Sal! Lake City. UT 84116-0660
(801) 538-6191
Mr. Harry B McGee
Michigan Department of
Public Health
3500 N. Logan Street
Lansing. Ml 48909
(517) 335-8165
Mr. G. Wade Miller
Executive Director. ASDWA
1911 N. Fort Myer Drive
Arlington. VA 22209
(703) 524-2428
Dr. Michael Moser
Kentucky Department of
Health Services
275 East Main Street
Frankfort, KY 40621
Mr. Robert L. Munari
Arizona Department of
Environmental Quality
16405 North 50th Lane
Glendale, AZ 85306
(602) 392-4002
Mr. Al E. Murrey
Idaho Department of Health
and Welfare
Division of Environmental
Quality
Water Quality Bureau
Statehouse Mail
Boise. ID 83720-9990
(208) 334-5860
Mr. Jay T. Ray
Louisiana Department of
Health and Hospitals
P.O. Box 60630
New Orleans. LA 70160
(504)568-5101
53
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Mr. Barry O'Brien
Maryland Department of the
Environment
201 West Preston Street
Baltimore. MD 21201
(301)225-6362
Mr. Kurt S. Patrizi
Safe Drinking Water Hotline
Geo Resource Consultants, Inc.
Waterside Mall
401 M Street, S.W.
Washington, DC 20024
(202)488-1487
Mr. Thomas P. Poleck
U.S. Environmental Protection
Agency
230 South Dearborn Street
5WD-TUB-9
Chicago, IL 60604
(312)886-2407
Mr. Frederick W. Pontius
Secretary
Regulatory Agencies Division
American Water Works Assn.
6666 West Qumcy Avenue
Denver. CO 80235
(303) 794-7310
Mr. Joe A. Power
Alabama Department of
Environmental Management
3200 Uttlejohn Drive
Montgomery, AL 36109
(205) 271-7773
Mr Michael P. Rau
Colorado Department of Health
4210 E. 11th Avenue
Denver, CO 80220
(303)331-4732
Mr Richard A Rogers
U-S. Environmental Protection
Agency
Drinking Water Section (3WM41)
841 Chestnut Building
Philadelphia. PA 19107
(215)597-8992
Ms. Shireene Sementi
Idaho Panhandle District
Health Department
2195 Ironwood Court
Coeur d'Alene, ID 83814
(208) 667-3481
Dr. Kazim Sheikh
West Virginia Department of
Health
151 11th Avenue
South Charleston, WV 25303
(304) 348-3526
Ms. Pamela J. Shillman
Colorado Department of Health
4210 E. 11th Avenue
Denver, CO 80220
(303)331-8343
Dr. Paul R. Silverman
Delaware Division of Public
Health
Bureau of Disease Prevention
P.O. Box 637
Dover, DE 19901
(302) 736-5617
Dr. James E. Smith, Jr.
U.S. Environmental Protection
Agency
26 W. Martin Luther King Drive
Cincinnati. OH 45268
(513)569-7355
54
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Mr. Mitsuto Sugi
Hawaii Department of Health
Epidemiology Branch
P.O. Box 3378
Honolulu. HI 96801-9984
(808) 548-2235
Ms. Sheila A. Sullivan
U.S. Environmental Protection
Agency
Region 5 (5WO-TUB9)
230 South Dearborn Street
Chicago IL 60504
(312)886-5251
Ms. Lori V. Talbot
Administrative Assistant
ASDWA
1911 N. Fort Myer Drive
Arlington, VA 22209
(703) 524-2428
Mr. Jeffery P. Taylor
Texas Department of Health
Epidemiology Division
1100 West 49th Street
Austin, TX 78756
(512)458-7328
Mr. Johnny B. Taylor
Oklahoma StaU Der ^nt
of Health
P.O. Box 53551
1000 Northeast 10th Street
Oklahoma City, OK 73152
(405)271-7372
Ms. Tina A. Timmerman
North Dakota State Department
of Health and Consolidated
Laboratories
Division of Disease Control
State Capitol
Bismarck, ND 58505
(701)224-2378
Mr. Raymond J. Vanisko
New Jersey State Department
of Health
Consumer Health Services
CN 364
Trenton. NJ 08625
(609) 984-3400
Mr. Arnold J. Viere
Indiana Department of
Environmental Management
5500 W. Bradbury
Indianapolis. IN 46241
(317)243-5084
Mr. David F. Waldo
Kansas Division of Environment
Forbes Field
Topeka, KS 66605
(913)296-5503
Dr. Sanford B. Werner
California Department of
Health Services
Infectious Disease Branch
2151 Berkeley Way
Berkeley. CA 94704
(415)540-2566
Mr. Daniel Wilson
Wisconsin Department of
Natural Resources
P.O. Box 7921
Madison, Wl 53707
(608) 266-7093
Ms. Julia M. Winter
Florida Health Department
1317 Winewood Boulevard
Building 6
Tallahassee. FL 32399-0700
(904) 488-2905
55
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Ms. Narda Tolentino Mr Leigh B Woodruff
Connecticut Department of U S. Environmental Protection
Health Services Agency
150 Washington Street 120 Sixth Avenue
Hartford, CT 06106 Mailstop ES-098
(203) 566-5058 Seattle. WA 98101
(206) 442-8087
Total Attendance
including Speakers: 128
56
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Uniied Stales
Envtronmental Protection
Agency
Center lor Environmental Research
Information
Cincinnati OH 45268
iiU> K HA1E
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EPA 600-9-90-021
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