[Federal Register Volume 63, Number 154 (Tuesday, August 11, 1998)]
[Notices]
[Pages 42849-42852]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-21343]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-6140-8]


Waterborne Disease Studies and National Estimate of Waterborne 
Disease Occurrence

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of data availability and request for comments.

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SUMMARY: The Safe Drinking Water Act (SDWA) Amendments of 1996, section 
1458(d), provides that within two years of enactment the Environmental 
Protection Agency (EPA) and the Centers for Disease Control and 
Prevention (CDC) will conduct pilot waterborne disease occurrence 
studies for at least five major U.S. communities or public water 
systems. Section 1458(d) also provides that, within five years of 
enactment, EPA and CDC will prepare a report on the findings of these 
pilot studies and develop a national estimate of waterborne disease 
occurrence (``the national estimate'').
    The purpose of this Federal Register document is to inform the 
public about how EPA and CDC are addressing this provision. The 
document includes descriptions of planned and ongoing epidemiological 
studies and discusses public involvement in developing an approach for 
estimating the national level of waterborne disease occurrence. 
Comments are requested on issues related to the epidemiological studies 
and to developing the national estimate.

DATES: Comments should be postmarked or delivered by hand on or before 
November 9, 1998.

ADDRESSES: Send written comments to Susan Shaw, (MC-4607); U.S. 
Environmental Protection Agency; 401 M Street, SW, Washington, DC 
20460, or by email to [email protected]. Comments may also be 
hand-delivered to Kimberly Miller, U.S. Environmental Protection 
Agency; 401 M Street, SW, Room 3809, Washington, DC 20460.

FOR FURTHER INFORMATION CONTACT: For further general information and 
for copies of the reports from the 1997 Atlanta and the Washington, 
D.C. workshops discussed herein, contact the Safe Drinking Water 
Hotline, Telephone (800) 426-4791. The Safe Drinking Water Hotline is 
open Monday through Friday, excluding Federal holidays, from 9 a.m. to 
5:30 p.m. Eastern Time. For technical inquiries, contact Susan Shaw, 
Office of Ground Water and Drinking Water (MC4607), U.S. Environmental 
Protection Agency, 401 M Street, SW, Washington, DC 20460; telephone 
(202) 260-8049; email: [email protected]. To receive 
additional information about the spring 1999 public meeting, contact 
Kimberly Miller, Office of Ground Water and Drinking Water (MC4607), 
U.S. Environmental Protection Agency, 401 M Street, SW, Washington, 
D.C. 20460; telephone (202) 260-0718; email: 
[email protected].

Abbreviations Used In This Document

CDC: Centers for Disease Control and Prevention
EPA: US Environmental Protection Agency
SDWA: Safe Drinking Water Act, as amended in 1986 and 1996

Table of Contents

1. Introduction and Statutory Authority
2. Background
3. EPA and CDC Actions and Strategy to Develop the National Estimate
4. Studies for Developing the National Estimate of Waterborne 
Disease Occurrence
    A. Cross-Sectional Gastroenteritis and Water Consumption Survey
    B. Triple-Blinded Household Intervention Pilot Study
    C. Household Intervention--Two Requests for Proposals
    D. Three CDC Requests for Proposals
    E. Community Intervention Studies
    F. Other Studies to Assist in National Estimate Development
5. Conclusions

1. Introduction and Statutory Authority

    The Safe Drinking Water Act (SDWA) Amendments of 1996, section 
1458(d), provides that within two years of enactment the Environmental 
Protection Agency (EPA) and the Centers for Disease Control and 
Prevention (CDC) will conduct pilot waterborne disease occurrence 
studies for at least five major U.S. communities or public water 
systems. Section 1458(d) also provides that, within five years of 
enactment, EPA and CDC will prepare a report on the findings of these 
pilot studies and develop a national estimate of waterborne disease 
occurrence.
    The purpose of this Federal Register document is to inform the 
public about how EPA and CDC are addressing the provision to conduct 
studies on waterborne disease occurrence and to develop a national 
estimate of waterborne disease occurrence due to drinking water (the 
``national estimate''). The document is organized as follows:
    Background: Discussion of the difficulties inherent in quantifying 
infectious disease due to drinking water.
    EPA and CDC actions and strategy to develop the national estimate: 
Describes

[[Page 42850]]

actions taken by EPA and CDC to conduct waterborne disease occurrence 
studies, and to develop the national estimate of waterborne disease 
occurrence; discusses overall strategy for complying with Section 
1458(d), including public involvement.
    Waterborne disease studies: Describes ongoing and planned studies 
funded by EPA that are expected to contribute directly to developing 
the national estimate of waterborne disease occurrence.
    Conclusions: CDC and EPA actions to date, and next steps, including 
public participation and request for comments

2. Background

    Although outbreaks of infectious disease attributable to drinking 
water are not common in the United States, they remain a concern and 
the extent to which they occur unrecognized by the health authorities 
has been the focus of much debate in recent years. One critical 
question of interest to those who are concerned about the microbial 
quality of drinking water and the associated health effects is: What is 
the magnitude of infectious disease in the United States that can be 
attributed to drinking water and, in particular, what are the levels of 
disease due to drinking water from public water systems that meet state 
and federal drinking water standards. There is no obvious and easy 
answer to this question. It is generally recognized that cases of 
waterborne disease are not likely to be recognized as such, and that 
therefore there is little direct information on which to base an 
estimate of waterborne disease occurrence and its associated costs to 
society. Illnesses caused by contaminated water are generally not 
specific to water, e.g diseases such as gastroenteritis could be caused 
by contaminated food or person-to-person transmission; moreover most 
cases will not result in illness deemed sufficiently serious by the ill 
person to require consulting a health care provider. Even if the 
disease is serious, it is highly unlikely to be traced back to drinking 
contaminated water unless the health care provider notices a sudden 
increase in the number of cases beyond what is normally expected, i.e. 
more cases than normal background levels within the population. In this 
case it is possible that the health authorities may be alerted and may 
consider that the increase in cases warrants an investigation which 
could lead to determining the vehicle of the disease agent, and thus to 
tracing the disease back to contaminated drinking water. This is only 
likely to happen in the case of an outbreak where a large fraction of 
the population has been infected. In order to detect any background 
levels of infectious disease due to drinking water, it is necessary to 
conduct targeted epidemiological investigations.
    The issue of waterborne disease detection and how to detect disease 
within a population that can be attributed to drinking water is 
discussed in the reports from the two EPA/CDC workshops described 
below. The reports are available from EPA through the Safe Drinking 
Water Hotline. This notice describes how EPA and CDC are proceeding to 
develop an estimate of the level of waterborne disease in the United 
States based on data from targeted epidemiological studies.

3. EPA and CDC Actions and Strategy to Develop the National 
Estimate

    EPA and CDC are working in close partnership to meet the 
requirements of the mandate to conduct studies on waterborne disease 
and to develop a national estimate of waterborne disease occurrence. 
Based on the legislative history, EPA and CDC interpret the term 
``waterborne disease'' to refer to waterborne disease due to disease-
causing microbes (pathogens) in drinking water, rather than to disease 
caused by chemical contamination. To the extent possible, EPA and CDC 
intend to consider which populations are at greatest risk, the economic 
impact of waterborne disease, which infectious agents are causing 
waterborne disease and their relative contribution to the overall 
incidence of waterborne disease due to drinking water, and the 
characteristics of water systems that are more likely to lead to 
waterborne disease.
    In developing an approach to address the SDWA mandate, EPA and CDC 
invited the participation of outside experts and the public in two 
jointly-sponsored workshops. An initial workshop of public health 
experts from universities and from state and federal government took 
place in Atlanta in March 1997. A follow-up public workshop with wider 
representation of experts and other interested persons was held in the 
Washington, DC area in October 1997. Through this process of 
cooperative deliberation, EPA and CDC sought to review existing 
knowledge on waterborne disease and associated factors, and to evaluate 
different study designs to provide data necessary for calculating the 
national estimate of waterborne disease occurrence. Detailed summary 
reports of both meetings, including a list of participants, are 
available from EPA.
    At the Atlanta workshop, attendees suggested that two components 
were needed to calculate a national estimate of waterborne disease: the 
incidence of gastrointestinal illness and the fraction of 
gastrointestinal illness attributable to drinking water. Cross-
sectional surveys of the population were suggested as a straightforward 
means of determining the incidence of gastrointestinal illness. The 
workshop then focused on reviewing different study designs for 
establishing the fraction of gastroenteritis in a population that is 
attributable to drinking water. The participants identified the 
strengths and weaknesses of various designs and suggested that each be 
further evaluated for possible systematic biases, methods available for 
controlling bias, number of participants needed for a statistically 
stable estimate of increased risk, and the feasibility of measuring the 
specific pathogens associated with observed waterborne disease. Most 
participants felt that a population-based study, e.g. a household 
intervention study, would provide the strongest epidemiological 
evidence of waterborne disease and was the best design to determine the 
attributable fraction. However, participants also felt that other study 
designs were useful for estimating the attributable fraction and that 
more convincing evidence of waterborne disease risk and its magnitude 
would be provided by implementing several different study designs, 
rather than relying on multiple studies of the same design.
    At the Washington workshop, specific ongoing and proposed studies 
and study designs were reviewed with respect to how they could 
contribute to the national estimate, and participants proposed 
alternate designs and combinations of designs. CDC presented an 
analysis of why it had decided to proceed with a pilot household 
intervention study. The participants again felt that it would be 
advantageous to conduct a variety of different study designs. This 
position is reflected in the request for proposals that was recently 
issued by CDC for three additional studies to provide data towards the 
national estimate in which the choice of study design is open to the 
researcher. In addition, EPA's in-house research program is conducting 
waterborne disease studies using other study designs.
    EPA and CDC plan to host another public workshop in the spring of 
1999 to review ongoing and planned studies and the need for specific 
additional information, and to discuss ideas on feasible approaches to 
developing the national estimate, taking cost and the development 
schedule into consideration. EPA and CDC welcome

[[Page 42851]]

comments on issues related to this proposed workshop, and encourage 
people who are interested in participating or who would like to receive 
notice of future meetings to notify EPA.
    Since the initial workshop in March 1997, a total of $3.0 million 
from EPA's fiscal year 1997 and 1998 appropriations has been 
transferred to CDC to allow funding for seven studies on waterborne 
disease occurrence: A pilot household intervention study, two full-
scale household intervention studies, a cross-sectional gastroenteritis 
and water consumption survey, and three epidemiological studies of 
unspecified design. CDC is managing the above projects; however, EPA 
and CDC work together in the review and selection of the study 
proposals. In addition to the above CDC/EPA collaborative studies, EPA, 
through its National Health and Environmental Effects Research 
Laboratory is funding research to characterize microbial enteric 
disease in a series of ``community intervention'' studies. These 
studies are described in more detail below.
    In combination, these studies will provide a considerable amount of 
new data to support the development of a national estimate of 
waterborne disease occurrence by August 2001. However, EPA and CDC 
share a concern that given the two to two-and-a-half year duration for 
completion of some of the studies (the two household intervention 
studies), some of the data may not have undergone a full review by mid-
2001. If this turns out to be the case, the national estimate will be 
revised if necessary by August 2002.

4. Studies for Developing the National Estimate of Waterborne 
Disease Occurrence

    This section provides a brief summary of EPA and CDC's planned and 
ongoing studies that will contribute to developing the national 
estimate, including the study objectives, design, and population. 
Information from other studies by other organizations on waterborne 
disease, and relevant aspects of water quality and water treatment, 
will also be considered in the development of the national estimate.

A. Cross-Sectional Gastroenteritis and Water Consumption Survey

    This study is being conducted as part of the CDC's FoodNet Survey, 
and is based on a randomized telephone survey to detect the incidence 
of foodborne disease, including gastroenteritis, at seven sites within 
the United States, including specific populations in California, 
Oregon, Minnesota, Georgia, New York, Maryland, and Connecticut. 
Approximately 9000 interviews are conducted annually. The questionnaire 
has recently been expanded to include questions on type and quantity of 
water consumption. The survey will provide data on which to base an 
estimate of the national incidence of gastroenteritis and national 
drinking water consumption patterns. The national incidence of 
gastroenteritis and the fraction of gastroenteritis that can be 
attributed to drinking water in a community (data from some of the 
studies described below) will provide useful information towards 
calculating an estimate of the national incidence of gastroenteritis 
due to drinking water. Other useful information from the survey 
includes data on measures of disease impact such as time lost from work 
or school, use of outpatient medical care, and hospitalization for 
gastrointestinal illness. However, the survey is unlikely to provide 
any information regarding causative pathogens or the relationship of 
water quality indicators with gastrointestinal illness.

B. Triple-Blinded Household Intervention Pilot Study

    This is an experimental study in which persons in different 
households are randomly assigned to drink regular tap water or 
specially treated water that is expected to be pathogen free. The 
difference in tap water quality is achieved by installing identical 
looking devices at the water taps of homes of both groups; however, one 
group receives a device that further filters and disinfects the regular 
tap water, whereas the other group receives sham devices that do not 
provide additional treatment. If the group with the sham device has a 
higher incidence of gastroenteritis than the otherwise similar group 
with the real treatment device (the ``intervention''), then the 
difference will be assumed to be attributable to contamination in the 
regular tap water. The ``triple blinding'' refers to the design feature 
of ``blinding'' the researchers, statisticians and participants until 
the end of the study as to which households have regular tap water and 
which the specially treated tap water. Of particular interest for this 
type of study is whether persons in the households can detect (i.e. are 
blinded to) whether they are drinking regular tap water or the 
specially treated water, since knowing what group they are in might 
bias their response regarding whether or not they experience 
gastrointestinal illness.
    CDC and EPA considered it necessary to perform a pilot study to 
test whether blinding is possible and to develop guidance regarding the 
logistics of future household intervention studies. The triple-blinded 
household intervention study design is favored because its random 
assignment of treatment reduces the effects of confounding, and the 
blinding of all participants avoids biases that affect most other study 
designs. The Atlanta workshop participants generally agreed that this 
study design, a so-called population-based intervention study, would 
provide the strongest epidemiological evidence of waterborne disease 
risk and the best estimate of the attributable risk due to drinking 
water. However, of all the studies evaluated, it is the most expensive 
to conduct. For this reason, EPA and CDC presently envision performing 
this type of study in only two large public water systems: a surface 
water site and a ground water site.
    The pilot study was awarded to the California Emerging Infections 
Program. The site selected for the study is the Contra Costa Water 
District in California. Specific data that will be collected in this 
pilot study include amount of water consumption; symptoms of 
gastrointestinal illness; results of stool, sera and saliva tests; and 
impact of illness. The study is expected to be completed at the 
beginning of 1999.

C. Household Intervention--Two Requests for Proposals

    In October 1998, CDC expects to issue a request for proposals for 
conducting two household intervention studies: One in a municipality 
receiving drinking water from a conventionally treated surface water 
source, and a second in a municipality with ground water source. In 
addition to determining the fraction of gastrointestinal illness due to 
drinking water, the project includes the collection of water quality 
and water treatment plant data in order to evaluate the relationship 
between water quality and disease incidence.
    Initial funding available for the epidemiological aspects of the 
two projects amounts to $1.8 million. Additional funds will be 
available to fully fund the projects and to collect water quality data. 
The projects are expected to be awarded in the spring of 1999.

D. Three CDC Requests for Proposals

    CDC issued a request for proposals for three additional studies to 
estimate the incidence of waterborne disease due to microbial 
contamination of drinking

[[Page 42852]]

water and/or to identify and describe the relationship between measures 
of water quality and health outcomes or evidence of infection due to 
gastrointestinal pathogens. The choice of study design is open to the 
researcher. Combined funding available for these projects amounts to 
$450, 000, and is anticipated to be awarded in the fall of 1998.

E. Community Intervention Studies

    EPA is conducting a series of community intervention studies that 
are designed to characterize microbial gastroenteritis associated with 
drinking water that originates from selected surface water and 
groundwater sources. By studying communities that are planning to make 
improvements to their water treatment systems (e.g., adding filtration 
units or changing disinfectants), a ``natural experiment'' can be 
conducted which evaluates the enteric disease that may be present both 
before and after the implementation of the new system. The specific 
objectives of the first community study, which was conducted between 
June 1996 and December 1997, were to: (1) Determine rates of 
gastroenteritis; (2) determine the relative source contribution of 
factors implicated in gastroenteritis; (3) identify the microbial cause 
of gastroenteritis; and (4) assess surveillance methods of 
gastroenteritis. The data collected during the study are currently 
being analyzed. A community for the next community intervention study 
has been identified and data collection is slated to begin in the fall 
of 1998. EPA is also considering communities that use either ground 
water or surface water supplies as possible sites for future studies. 
EPA would welcome suggestions from the public on additional community 
studies.

F. Other Studies To Assist in National Estimate Development

    In its development of the national estimate of waterborne disease 
occurrence and interpretation of the data from the epidemiological 
studies, EPA and CDC expect to use data from other relevant studies and 
databases. Information to be considered includes completed or ongoing 
epidemiological studies not specifically associated with the EPA/CDC 
effort, data on pathogen occurrence currently being collected by many 
utilities, studies on the effectiveness of water treatment, the dose-
response relationship of certain pathogens, and studies on factors that 
affect the susceptibility of persons to infectious disease and disease 
severity.

5. Conclusions

    EPA and CDC have committed to conducting waterborne infectious 
disease occurrence studies in at least five major U.S. communities or 
public water systems. One such study--a community intervention study--
is nearing completion and a second community intervention study is 
scheduled to begin this fall. A pilot study for the two household 
intervention studies is underway and the two full-scale household 
intervention studies are expected to be awarded by April 1999. Three 
additional epidemiological studies of non-specified design are expected 
to be awarded in the fall of 1998.
    In 1997, at two public workshops, EPA and CDC proposed one possible 
approach to developing the national estimate. However, EPA and CDC 
intend to continue the dialogue on this and other approaches to 
developing the national estimate at a public meeting scheduled for late 
next spring. EPA will announce the meeting in the Federal Register; 
however, to facilitate planning the meeting, EPA suggests that people 
who are interested in attending the meeting, or in receiving additional 
information about the meeting, notify EPA now (see section FOR FURTHER 
INFORMATION above) . EPA and CDC welcome comments on the issues 
discussed in this notice, as well as the reader's opinion on the extent 
to which, and how, the national estimate should address the social and 
economic impact of waterborne disease, the contribution of specific 
pathogens to the prevalence of waterborne disease, and the 
characteristics of public water systems and water quality indicators 
that are associated with a higher risk of waterborne disease. (For 
information on whom to address comments, see section ADDRESSES above.)

    Dated: August 3, 1998.
J. Charles Fox,
Acting Assistant Administrator for Water.
[FR Doc. 98-21343 Filed 8-10-98; 8:45 am]
BILLING CODE 6560-50-P