United States
Environmental Protection
Agency
Office of Water
(4601)
EPA810-R-95-001
March 1995
&EPA
STRENGTHENING THE SAFETY OF
OUR DRINKING WATER:
A Report on Progress and Challenges
and An Agenda for Action
Recycled/Recyclable
pdntodwtlhSoy/Canolalnkonpaperthat
contains at least 50% recycled fiber
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Dear Reader:
Strengthening the safety of our nation's drinking water is among the highest
priorities of the Clinton Administration. When we ensure that title water we drink every
day is safe, we have protected the public health of our communities in the most
fundamental, common-sense way. After decades of effort to improve our drinking water,
Americans can generally turn on their taps without worry.
However, remaining safety problems, recent emergencies and the discovery of new
and emerging threats have prompted us to conclude that we can no longer take the safety
of our drinking water for granted. This report reviews the progress we have made toward
the goal of safe drinking water for all communities, as well as problem areas and
information gaps that threaten the safety of our drinking water. It sets forth an Agenda
for Action with five steps we can take to strengthen the protections on which Americans
rely.
EPA will continue to work with the Congress to achieve balanced reforms that will
strengthen the federal Safe Drinking Water Act But we must also act now to provide the
protection that will give the American people the safe drinking water they have come to
expect.
Governments, consumers, communities, states and tribes, water suppliers,
environmental organizations, public health officials and others must work together to take
these common-sense steps. Together, we must redouble our efforts, so we can give the
American people the safe drinking water we all want.
Since:
Carol M. Browner
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Table of Contents
Executive Summary {
Progress in Protecting Our Drinking Water J
The Public Health Benefits of Safety Standards 1
A Review of What's Known About Drinking Water Safety 2
What Does Drinking Water Safety Cost? '.'.','. 4
Why Americans Value Safe Drinking Water 5
Future Public Health Threats to Our Drinking Water ... 7
An Agenda for Action JO
1. Give Americans More Information About Our Drinking Water 10
2. Focus Safety Standards on the Most Serious Health Risks ...... 11
3. Provide Technical Assistance to Protect Source Water and Help
Small Systems 13
4. Reinvent Federal-State Partnerships to Improve Drinking Water
Safety 15
5. Invest In Community Drinking Water Facilities to Protect Human
Health 16
Appendix: Subjects for Stakeholder Meetings A-l
Regulatory Reassessment ., '. , A-l
Scientific Data Needs A-l
Treatment Technology A-l
Health Assessment A-2
Analytical Methods . A-2
Source Water Protection A-2
Small Systems Capacity Building A-2
Focusing and Improving Implementation A-3
i
Sources
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EXECUTIVE SUMMARY
Thanks to decades of concerted effort, Americans can generally turn on our taps
without worry about the quality of the drinking water that flows out. Providing safe
drinking water to all Americans is a goal that makes both economic and environmental
sense, affecting everything from the safety of our children to decisions about where we
live and work.
Yet, many important questions about drinking water safely remain unsettled.
To provide some answers, EPA reviewed available information, including recent safety
testing data from public water supplies, scientific studies on the health effects of
microbial contaminants, and studies of factors that affect drinking water sources. We
found that while most American households receive safe drinking water, there are
pockets of serious trouble, gaps in information, and newly recognized and emerging
threats to drinking water safety. This review identifies the need to redouble our efforts
in key areas, to find new solutions that target health priorities and prevention, and to
build stronger partnerships.
Recent events and growing public concerns suggest that we can no longer take
the safety of our drinking water for granted. In 1993, over 400,000 Milwaukee
residents became ill from drinking water contaminated by the microbe
Cryptosporidium, and some 100 deaths have been attributed to that contamination.
Later that same year, two of the nation's largest cities - New York City and
Washington, D.C. advised their residents temporarily to boil drinking water to protect
against the risk of contamination.
In addition, rising awareness of pollution and other environmental problems has
raised consumers' concern about drinking water safety:
* A 1993 Roper survey found that nearly one-third of Americans believe their
drinking water is either contaminated or are very concerned it may become
contaminated in the future.
t Rising sales of bottled water - now annually exceeding 2.2 billion gallons with
an estimated wholesale value of over $2.4 billion have been linked, in part, to
concerns over tap water safety and quality.
* Surveys show that four out of five people support measures to improve drinking
water safety.
EPA's review indicates that microbiological contaminants and their disinfection
are among the greatest near-term challenges to safe drinking water - - particularly
those such as Cryptosporidium, which may be resistant to traditional disinfection
methods. We also need a stronger national commitment to prevention.
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In 1994, some 30 million Americans were served by drinking water systems that
violated one or more public health standards. Most of these violations were of
microbiological standards, threatening near-term, acute illness. States have identified
over 1000 community water systems serving roughly 13 million people that need to
install filters for their supplies'to protect against micfobial threats.
Other violations, of chemical standards, create a risk of chronic health effects if
consumption of contaminated drinking water continues over the long run. One out of
four systems conducts or reports the results of only part of the water tests required to
verify safety.
Among the greatest future challenges are the needs to remedy decaying drinking
water infrastructure, deal with remaining contamination threats, and better
understand and create stronger protection against waterborne diseases.
Building on our current efforts, we need to do more to protect drinking
water safety, focusing on the greatest health risks and taking the most
effective actions to prevent problems. EPA reaffirms its strong support for balanced
changes that will strengthen the present federal Safe Drinking Water Act and will
continue to work with Congress to secure such changes. But there is much we can do
now to achieve more protection and flexibility. This includes the following Agenda for
Action containing five specific, common sense solutions:
1) Give consumers more information about the quality of their drinking
water, so they can better participate in solutions to any problems.
2) Target safety standards, research and resources first at contaminants
that pose the greatest threats to human health, including greater protection
against microbial contaminants.
3) Provide technical assistance to more small systems, communities and
states for greater protection of source waters, better facility operation, and to
prevent other problems.
4) Give states more flexibility to address their individual problems and set
program priorities, including monitoring regimes.
5) Increase investment in community drinking water facilities through such
vehicles as a federal loan program.
For all of these solutions, EPA is seeking greater stakeholder involvement to help
define how to carry out our Agenda to improve drinking water protection. Such
involvement is needed to craft solutions that are effective and practical in
strengthening the safety of our drinking water.
ii
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PROGRESS IN PROTECTING OUR DRINKING WATER
Some reports on drinking water
seem alarming, while other voices sug-
gest all is well. A review of available
information on drinking water shows
the truth is likely somewhere in be-
tween. Many gains have been made in
drinking water protection, and most
households in the United States now
receive water that meets current EPA
safety standards. However, there are
also pockets of serious trouble, as well
as newly recognized and emerging
threats to drinking water safety. To
maintain past gains and achieve further
progress, we need to make significant
changes to our approach.
The Public Health Benefits of
Safety Standards
Since the Safe Drinking Water Act
was enacted in 1974, and subsequently
revised in 1986, EPA has established
safety standards for 84 contaminants,
including specific treatment require-
ments for systems that use surface
water (e.g., rivers, lakes) and for
communities where lead in drinking
water is a problem. These safety
standards define either the maximum
level at which a contaminant is allowed
in water delivered to the tap, or specify
All references to U.S. households include
only those households connected to public water
systems, which are defined to include both publicly-
and privately-owned systems regularly serving 25
persons or more. J5PA estimates that 90 percent of
U.S. households rely on public water systems for
their primary water supply, and the rest rely on
individual, domestic water supplies. Non-public
water supplies are not regulated for safely under
the Safe Drinking Water Act
certain types of treatment for contam-
inants that are difficult to measure.
Water suppliers are responsible
for ensuring that 1tap water meets
federal and state {safety standards.
When current safety standards are
attained, the following estimated health
benefits are expected to accrue:
4 Reduced lead exposure for an
estimated 50 million people, and
as a result, protection for
200,000 children against
unacceptable levels of lead in
their blood. Lead can impair
mental development in children.
* Prevention of well over a hundred
thousand cases of gastro-
intestinal illness and other
illnesses attributed to micro-
organisms sinnually.
4 Reduced exposure for millions of
people to dozens of contaminants
that may csiuse illness including:
compromised reproductive cap-
abilities; liver, heart, thyroid* and
kidney malfunction; blue baby
syndrome; and damage to the
nervous system.
* Over 100 excess cancer cases
avoided per year from :
carcinogens; such as ethylene
dibromide, vinyl chloride, radium
and others.
These are national estimates of
benefits. It is often ve:ry difficult if not
impossible to estimate benefits at the
local level due to variation in contam-
ination risks and population char-
acteristics. Even the concept of
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One of the most Important
concepts to understand about the
Earth's water is that it Is not pure.
Because water is the universal solvent^
many natural and human made
materials are easily dissolved upon
contact The level of certain
substances in water ("contaminants"}
determines whether the water is safe ,
to drink. Contaminants include
microbes (bacteria, viruses, and
protozoa), chemical substances
(metals, minerals, and both organic and
inorganic chemicals) and radioactive
threats (rocttum; radon, and others).
Some of these substances include
essential nutrients, while others may
pose short-term (i.e., acute) or long-.
term (i.e.,.chronic) health threats;
Since the early 1900's, the use of
disinfectants, such as chlorine, has
vastly reduced diseases caused by *
microbiological contamination. The
Safe Drinking Water Act creates a
federal, state, and local partnership ,
designed to reduce remaining threats
from microbiological contamination
and to address chemical and
radiological contamination.
"benefit" is difficult to define. For
example, many people might consider
increased "safety" (or the simple know-
ledge that their water is safe) to be a
benefit even if the "cases of illness
avoided" due to water treatment are low.
A Review of What's Known
About Drinking Water Safety
Water testing is the best way to
verify drinking water safety in any
specific location. Water suppliers are
required to conduct testing (termed
"monitoring") to determine whether
drinking water quality meets safety
standards established under federal
(and often state) law. Consumers can
request the results of water tests con-
ducted by their water systems from
their local water supplier. Whenever
testing shows the levels of a contam-
inant exceed a drinking water safety
standard, the water supplier is
required to reduce the level of the
contaminant and to report the exceed-
ance of the standard ("violation") to its
customers as well as to the state, which
in turn reports the violation to EPA.
Information on violations alone
does not present a complete picture on
drinking water safety. Some violations
may be serious, while others may be
less so. This type of information also
cannot be used to determine if the level
of contamination is generally rising or
falling. The states, EPA, and water sys-
tems are working to improve data on
drinking water. Despite current
limitations, available data do shed some
light on the issue of drinking water
safety.
Based on past data reported by
states, EPA estimates that roughly 10
percent of households (about 30 million
people) typically receive water over the
course of 12 months from a water
system with one or more violations of
federal safely standards or treatment
requirements. Most of these violations
People with their own water wells or
special concerns about water safety can hire a
qualified laboratory to test their water. Information
on water testing can be obtained, from EPA's Safe
Drinking Water Hotline (tel. 1-800-426-4791).
**Except as otherwise noted, the sources of
data presented in this section are: The National
Public Water System Supervision Program Com-
pliance Report, FY 1993 and FY 1994 (draft), U.S.
Environmental Protection Agency.
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are of microbiological standards,
threatening near-term, acute illness;
violations of chemical standards create
a risk, if consumption of contaminated
drinking water continues over the long
run, of other, chronic health effects.
As for the remaining households,
most probably receive safe drinking
water year-round, but many water
systems don't conduct sufficient testing
to be sure. In fact, one system out of
every four conducts or reports the
results of only part of the monitoring
required to verify drinking water safety.
Although failure to monitor does not
necessarily correlate to safety problems,
EPA, state agencies, and consumers
cannot determine the degree of drinking
water safety in communities where
monitoring is inadequate or unreported.
These systems may or may not be in
compliance with safety standards.
Failure to monitor (or report) is
most common for indicators of
microbiological contaminants (e.g.,
bacteria) and lead* Out of the nation's
57,000 systems serving year-round
residents ("community" water systems),
8,400 systems (serving 15 million
people) violated microbiological
monitoring requirements and 8,300
systems (serving 8 million people)
violated lead monitoring requirements
in 1994.
*
Part of the explanation for high
microbiological and lead monitoring violations is
that more monitoring (for more systems) is required
for these contaminants than for others. Water
systems are now in the process of monitoring for
additional chemical contaminants, and these
monitoring results will be available in 1996.
Another indicator of drinking
water safety is whether water systems
are using filtration or other treatment to
control contaminants likely to be found
in their source water (e.g., rivers, lakes).
Water suppliers across the country are
working to meet recent requirements
that surface water be filtered before it is
provided as drinking water, except
where systems are allowed to avoid
filtration because the water meets
specific measures of quality. Despite
considerable progress in meeting this
requirement, states in 1994 identified,
as pockets of potential trouble, over
1000 systems serving roughly 13 million
people that need to filter to protect
against waterbome disease threats.
As water systems work to meet
existing standards, there are signs that
current protections may not be enough,
particularly for some types of micro-
biological contamination. Most experts
believe that, under certain conditions,
an outbreak on the scale of Milwaukee's
is possible in other regions of the United
States. Out of a total population of 1.6
million in Milwaukee's service area, an
estimated 403,000 became ill from the
waterborne parasite Cryptosporidium
during the outbreak in 1993,1 and some
100 deaths have been attributed to that
contamination.
In the past two years, residents
of Racine, Wisconsin, parts of New York
City, and a large portion of the
Washington, D.C. metropolitan area
were advised as a precaution to boil
their tap water due to heightened risk of
microbiological contamination. In
addition to the 7.5 million people served
by these water systems, states reported
that over 850 cornmiunity water
systems, collectively serving well over
one million people, were ordered to
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issue "boil water" advisories over the
last two years.* Many water suppliers
advise consumers to boil their water as
a precaution when a problem is
discovered. In these instances, timely
action by the water system or state
works to protect the public against
temporary or short-term risks. In other
cases, "boil water" advisories may in-
dicate a more fundamental or ongoing
water treatment problem. Because
information on "boil water" advisories is
voluntarily reported by the states (not
required), additional information on the
nature of these actions is unavailable.
Unlike threats from microbio-
logical contamination, which are com-
mon in source waters, chemical threats
to drinking water safety are more diffi-
cult to characterize nationally. They
vary greatly based on local geology that
may cause natural contamination (e.g.,
radon), and local activities (such as
mining, manufacturing, transportation),
chemical spills and other emergencies,
underground waste injection, or land
use patterns, including agricultural
practices. Some types of contaminants,
however, such as nitrates (linked to
agricultural practices, septic systems
and other sources) and petroleum
products (linked to storage tanks and
petroleum facilities), are widely found
across the U.S. Nationally, over two
million people were served by a system
that violated federal safety standards for
chemical contaminants in 1994.
*This number likely understates the
number of people advised to boil their water before
drinking. It does not Include (1) people served by
systems that voluntarily issued "boil water"
advisories; (2) advisories Included as part of an EPA
or state enforcement action; and (3) advisories not
reported by the state to EPA.
What Does Drinking Water
Safety Cost?
Most water customers are
accustomed to paying water bills for "on
demand" water service, including an
adequate supply at adequate pressure
around the clock. To provide this
service, water system revenues must
cover everything from basic operation
and maintenance to investments in new
equipment and distribution systems. In
addition, a portion of the water system
revenues must also cover the somewhat
"hidden" cost of meeting safety
standards ~ whether it's to pay for
water testing or to install new treatment
facilities. The benefits of drinking water
protection have already been discussed
above. But what about costs? As
communities grapple with increasingly
difficult funding decisions for competing
needs, questions about costs are on the
minds of public officials nationwide.
National cost estimates vary
because it is difficult to predict how
many systems will need to invest in
treatment to meet a standard and how
much that treatment will cost. Based
on data available to EPA at the time
current standards were issued, the
national costs specifically attributable
to drinking water safety under the Safe
Drinking Water Act (not counting
normal water supply operations,
investments, maintenance, repairs, etc.)
was estimated to be $ 1.4 billion
annually to meet existing safety
standards.
* The average effect on household
water bills is a projected increase
of 25 cents to $2.00 per month
for 90 percent of U.S.
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households in order for water suppliers
to meet existing safety standards.2
Due to variation from place to place,
costs will be higher for some
households, and lower for others.
f More than two-thirds of the
national costs are for controls on
microbiological contamination
and lead.
+ Monitoring costs over a nine-year
period range from an average of
1 cent to 35 cents per month
for 9O percent of households.
For the smallest systems, how-
ever, these average costs could
exceed $10 per month in some
cases.
The large disparity in costs
between large systems and small
systems, as well as many other
sources of local and State variation,
means no single cost estimate is
"right"for any specific community.
As water suppliers work to reduce
remaining priority risks, cost will likely
rise generally, but will have greater or
lesser local impacts. The most
important impact may be an even
greater disparity in costs between large
and small communities. The increase
in overall household costs resulting
from Safe Drinking Water Act regu-
lations in some small communities
(which comprise just 10 percent of the
population) already could be 10-times
higher than the nationwide average.
*
Costs in some small communities (serving
10% of the population) may be 10 times higher than
average.
Why Americans Value Safe
Drinking Water
One key question for public
officials is, "How much are people
willing to pay for drinking water
protection?" Survey data can help
answer part of this question:
4 A 1993 Roper survey
commissioned by the National
Geographic Society found that:
* Nearly one-third of
Americans believe their
drinking water is either
contaminated or are very
concerned it may become
contaminated in the near
future;
* 83% of Americans rate the
upgrading of municipal
water treatment systems
as an excellent or good
idea; and
» 76% support this
measure, even (fit
raises rates.3
+ A 1993 survey published by the
American Water Works Assoc-
iation Research Foundation
supports this finding. The survey
found that:
* 74% of water customers
were willing to pay more
to raise water quality
above the federal
minimum standards; and
» 82% were willing to pay
more to meet existing
federal standards.4
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Water quality consistently rates
high among "quality of life"
indicators.
What surveys have not identified,
however, is how much people are
willing to pay for certain levels of safety,
or how much they will pay for activities
which do not directly affect safety, such
as monitoring. Monitoring alone does
not provide safety; it only identifies
problems or verifies safety. If water
testing shows the water is free of
contamination, the "value" of
monitoring is simply the assurance, or
peace of mind, that comes from
verifying the safety of the water. One
indication of people's willingness to pay
for more safety is rising sales of bottled
water -- now annually exceeding 2.2
billion gallons with an estimated
wholesale value of over $2.4 billion.5
Even though the concept of
"safely" may be hard to define, most
people seem predisposed to want it and
are willing to pay for it. Environmental
and consumer groups have suggested
that improved public information and
education on all facets of "safety"
including monitoring, source water
quality, and treatment needs ~ can help
water systems focus on priority
concerns, and tap into public support in
order to obtain funding necessary for
investments in water system
improvements.
Meeting future public demands
for safe drinking water will require both
continued citizen support and a more
effective and focused program that
achieves results. The public seems
willing to support safety improvements,
but such support cannot be taken for
granted as local funds are stretched to
meet competing demands.
*In 4 out of the last 5 years "clean water"
was the top ranked factor in Money magazine's
Annual Survey of Best Places to Live in America.
September 1994.
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FUTURE PUBLIC HEALTH THREATS TO OUR
DRINKING WATER
In 1990, EPA's Science Advisory
Board, an independent panel
established by Congress, cited drinking
water contamination as one of the
highest ranking environmental risks.6
More recently the Board identified four
trends for drinking water that have
significant implications for future
protection efforts:7
* Increased population growth
resulting in diminishing supplies
of good quality water sources;
* Public demand for increasingly
cleaner drinking water;
* A changing profile of chemical
and resistant microbial
contaminants that may pose
public health concerns; and
* Economic and technical
pressures that will fundamentally
change the manner in which
drinking water is produced and
the need to replace and repair
aging infrastructure.
These trends will pose new and
difficult challenges for the nation's
water suppliers. How will water
suppliers meet rising demands for high
quality tap water at a time when
sources of water lakes, rivers, and
ground water ~ are increasingly
threatened by population pressures and
pollution? How will water systems meet
future treatment challenges while still
catching up on past infrastructure
needs? Health concerns for sensitive
subpopulations (e.g., pregnant women,
people with weakened immune systems)
requiring a greater margin of safety will
make these challenges even greater.
The Science Advisory Board
reported that microbiological
contaminants (e.g., bacteria, protozoa,
viruses) once thought to be almost
conquered by modem disinfection
techniques are likely the greatest
remaining health risk management
challenge for drinking water suppliers.
Growing evidence of familiar and
emerging threats caused by disease-
causing microorganisms (pathogens)
calls for increased research and
renewed vigilance in. the fight against
microbiological contamination of
drinking water. Heightened awareness
of poorly understood contaminants,
such as Cryptosporidium (the contam-
inant behind the Milwaukee disease
outbreak), will require water suppliers
and ultimately, water consumers, to
invest millions of dollars in information
collection and research, and more in
eventual drinking water protection.
Microorganisms such as Crypto-
sporidium, because of their small size
and resistance to conventional
disinfection, present a significant
challenge for water suppliers.
The control of microbiological
contaminants is further complicated
because commonly-used disinfection
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processes themselves may pose serious
health risks. Conventional practice
requires the addition of disinfectant
chemicals to the water that, while
effective in controlling many harmful
microorganisms, combine with organic
matter in the water and form com-
pounds known as disinfection by-
products, some of which may cause
cancer, liver and kidney damage, heart
and neurological effects, and effects on
unborn children. One of the most
complex questions facing water supply
professionals is how to minimize the
risks from disinfection byproducts yet
still control microbial contaminants.
Other pathogens may need
further investigation, such as the
bacterium Helicobactor pylori, which is
linked to gastritis, peptic ulcers and
gastric cancer;8 9 10 Hepatitis E;11 and
the protozoa Microsporidvum and Cyclo-
sporo,12 13 which have been linked to
gastrointestinal illness. "Biofilms" that
form on the inside of water pipes are
known to harbor bacteria that may
cause infections in people with weak-
ened immune systems.14.15 Insufficient
data has been collected on the occur-
rence of these microorganisms in U.S.
water supplies; however, there is evi-
dence that some or all of these path-
ogens are potentially transmitted by
water. More research is needed on
methods of detection, occurrence in
water, levels that may cause harm, and
treatability of these emerging concerns.
In addition, new data are challenging
the assumption that most ground water
systems are free from microbiological
contamination. Indeed, most of the
documented outbreaks of waterborne
disease in recent years have occurred
among populations using ground
**
water.
In addition to microbiological
threats, trends in both urban and rural
settings are likely to pose chemical
threats to current and future supplies
of safe drinking water. Many common
sources of contamination leaking
underground storage tanks, urban
stormwater runoff, municipal and
industrial discharges and impound-
ments are especially concentrated in
urban and suburban settings. Another
threat to drinking water may occur in
areas not served by public sewers where
industrial and commercial wastes are
disposed through underground in-
jection into septic systems or dry wells.
Urban uses of land more than
tripled since the 1950's, rising from
18.3 million acres to 56.6 million
acres.16 Growth-related water
contamination "is significant because
the areas of contamination generally
occur near population centers with a
high demand for clean [drinking]
water."17 Population growth and the
expansion of urban land use are likely
to pose new risks of contamination in
areas that may not have been at risk
just a few years ago.
In rural areas, the levels of
chemicals used in agriculture, including
pesticides and fertilizers, have stabilized
in recent years at double the levels used
in the 1960's.18 While improved
management practices for animal
wastes and fertilizers, and the
increasing use of safer pesticides and
Conventional disinfection may not be
adequate to control Cryptosporidiwn and some
other microbes.
Based on a review of Morbidity and
Mortality Weekly Report, Centers for Disease Control
and Prevention, since 1992.
8
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integrated pest management practices
should help slow threats from
agriculture, these sources remain
concerns. For example, based on data
provided by states, agriculture is the
leading source of water quality s
impairment in our nation's rivers,
affecting 72 percent of impaired river
miles.19 In addition, it is estimated that
4.5 million people are exposed to levels
of nitrate (a contaminant of concern for
infants) from ground water wells above
EPA's drinking water standard.20
The Science Advisory Board
noted that national efforts to respond to
emerging trends and to head off future
threats to drinking water safety are
hampered by the existing requirement
in the Safe Drinking Water Act that EPA
regulate 25 new contaminants every 3
years. This numerically-driven
approach can force action even if data
on a contaminant's health effects and
Occurrence are incomplete, while
limiting the ability to focus
efforts on high-priority, high-risk
contaminants.
Outdated and deteriorated
drinking water infrastructure also
poses a fundamental long-term threat
to drinking water safety in the United
States. "Infrastructure" includes the
water treatment facility itself, the
distribution system, and other
associated pipes, tanks, storage
facilities, etc. Deferred maintenance
arid replacement of deteriorated
infrastructure can hinder drinking
water treatment and distribution, and
in some cases can cause
contamination. Leaking or decaying
water distribution systems (mainly the
pipes conveying water) provide ready
avenues for water contamination from
sewage or other contaminants ~ raising
risks of contamination at the tap. The
Science Advisory Board wrote that
"(distribution systems, particularly, will
need replacement on an ever increasing
basis throughout: the nation." Lead
pipes, now banned in new construction,
are a potential problem for older
systems. Many drinking water
treatment facilities are inadequate for
modern threats to water supplies, and
over 1000 unfiltered surface water
systems need basic water filtration.
Drinking water infrastructure is
not addressed under the current Safe
Drinking Water Act, but President
Clinton has requested a total of $1.8
billion for fiscal years 1994, 1995 and
1996 for a new Drinking Water State
Revolving Fund (DWSRF). Under the
DWSRF, states would receive federal
funds which they in turn would provide
to communities in the form of low
interest loans to pay for improvements
in drinking water protection. However,
Congress must appropriate these funds
and pass drinking water legislation
authorizing the DWSRF before EPA is
authorized to provide these funds to
states.
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AN AGENDA FOR ACTION
Many stakeholders -- including
states and tribes, water suppliers, local
agencies, and consumer and
environmental organizations, among
others -- believe more can be done
under the Safe Drinking Water Act to
protect public health. All partners in
drinking water protection recognize that
continued strong public support for
drinking water protection must be
answered with results, and better
results may be achieved by targeting
high priority public health concerns and
taking steps now to avoid future
problems.
This agenda for action proposes
key common sense changes in the
nation's system of drinking water
protection. These initial changes will
help set a new direction in drinking
water protection toward: (1) engaging
consumers in drinking water protection;
(2) better targeting of priority health
risks; (3) stronger community preventive
approaches; (4) streamlining and
focusing implementation of existing
safety standards; and (5) investing in
the nation's drinking water infra-
structure. EPA will also consider, in
consultation with stakeholders,
additional actions to support this new
direction.
As a first step, EPA has begun
holding public meetings to obtain
stakeholders' views and suggestions
regarding both the changes that EPA is
initially proposing and other possible
actions. The attached appendix
provides descriptions of the subject
areas for these meetings.
While most of the changes that
EPA is initially proposing can be
achieved under current law, the Agency
continues to support amendments to
the Safe Drinking Water Act that
strengthen and streamline drinking
water protection in the United States.
EPA provided recommendations to
Congress for reauthorization of the Act
in October 1993.
1. Give Americans More
Information About Our
Drinking Water
Informed and involved citizens
can be strong allies of water systems
small or large -- in taking effective
actions on pressing problems.
Involvement starts with information,
since an understanding of drinking
water conditions helps ratepayers recog-
nize the need for problem-solving
actions by their community water
system or state.
The American Water Works
Association Research Foundation 1993
Consumer Survey identified "Public
Involvement, Communications and
Trust" as a key area for utilities'
attention. The survey found that
consumers typically felt uninvolved in
decisions affecting their water supply.
Nearly two-thirds (64%) of respondents
surveyed said they received "very little"
or "no" information about the quality of
their drinking water. Almost njne out of
ten consumers said it was important
10
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that they receive more information, and
over 80% said the public should have
"more say" in matters involving their
drinking water supplies. In a report on
the survey, the American Water Works
Association Research Foundation
concluded that, "(c)learly the public
desires more information on water
quality issues, and the industry stands
to benefit from any effort to showcase
its concern as well as its willingness
and ability to respond to water quality
challenges."
2. Focus Safety
Standards on the Most
Serious Health Risks
Under the original 1974 Safe
Drinking Water Act, EPA's authority to
establish drinking water safety
standards was discretionary. Over the
following twelve years, heightened
concern over drinking water safety,
coupled with the perception that EPA
was moving too slowly to establish
standards, prompted Congress to
require a more directive approach in the
1986 amendments to the Safe Drinking
Water Act These amendments required
EPA to set standards for a list of 83
contaminants and an additional 25
contaminants every 3 years.
EPA has issued standards for all
but seven of the 83 contaminants and is
now working to develop standards for
the first group of 25. Despite past
progress in addressing many high risk
drinking water contaminants under this
approach, the 1986 amendments are
creating new problems. Some
standards established under this
approach may be of questionable value,
yet they divert resources at all levels
federal, state and local - from
addressing high priority risks. Worse,
resources needed to address new, high
risk contaminants may not be available
because of the need to meet these
statutory requirements under court-
11
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Agenda Item 2: Focus Safety Standards on the MostSeripiis
Health Risks
*. ff __ j.
EPA is seeking extensions of a number of court-order^ deadlines
for issuing drinking water regulations and wilt consulipffiC-*' }
stakeholders to: (1) identify priority health risks; arid;j&)dpvela$ a ''<*
regulatory plan reflecting risk-based priorities. ".'' ," r *p" ^ '"- "
In the short term, EPA plans to participate actively in owthjtiqjfog", \
by water utilities to optimize control of^microbioiogical contamination,
using existing, in-place waterjtttration systems. ; /,*-''",,> '.''I
ordered schedules. Many water sup-
pliers and government ofiBcials at all
levels ~ those on the front lines of
public health -- believe the Safe Drink-
ing Water Act should have more flex-
ibility in many areas and focus more on
the types of contamination that pose
the greatest risks to health.
A more flexible approach is
needed, and EPA has recommended
that Congress change the Safe Drinking
Water Act to allow more focus on health
risk priorities. However, until Congress
completes work on this matter, EPA is
seeking interim extensions of a number
of court-ordered deadlines to allow the
Agency to meet with stakeholders to
identify health risk-based priorities and
to develop a regulatory plan reflecting
these priorities. EPA would then seek
revised court-ordered schedules to re-
flect the priorities. While scientists,
drinking water suppliers, public interest
groups, and government agencies gener-
ally agree that microbiological contam-
ination of drinking water supplies re-
mains a serious concern, there is less
consensus among experts on the risk
reduction obtainable from other regu-
lations now on court-ordered schedules.
Meanwhile, EPA plans to sharpen
the focus of research necessary to
support safety standards for micro-
biological contamination (including
Cryptosporidium) and disinfection
byproducts. While EPA has long
conducted research in these areas,
revitalized efforts are needed in four
areas to support new standards: (1)
surveys to determine the levels at which
contaminants occur in source water
and drinking water; (2) development of
practical and reliable methods of testing
for contaminants (or appropriate in-
dicators), particularly pathogens re-
cently recognized as drinking water
threats; (3) improved additional health
effects information in order to assess
the risk posed by various waterbome
pathogens and the chemical byproducts
of disinfection; and (4) improved drink-
ing water treatment approaches, partic-
ularly for small systems.
EPA is also developing a broader
agenda to conduct research on the com-
parison, characterization and control of
risks associated with drinking water
12
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contaminants and various disinfectants
and their byproducts. In addition, sev-
eral joint research projects are being
planned or carried out with non-
governmental groups to support priority
research needs, including the American
Water Works Association Research
Foundation (on disinfection and micro-
bial issues), the Chemical Manufac-
turers Association (on the health effects
of alternative disinfectants), the Na-
tional Academy of Sciences (on small
system treatment technologies and
other solutions) and the National Water
Research Institute (on the movement of
viruses in ground water). Some water
suppliers and drinking water organi-
zations also have shown an interest in
supporting research on the risks of ar-
senic in drinking water. EPA is plan-
ning to cooperate with this effort by
identifying research priorities to support
an update of the existing drinking water
standard for arsenic.
Much can be done to improve
drinking water now while research
moves forward. Many water systems
are taking voluntary steps immediately
to reduce threats of microbiological
contamination. Although more infor-
mation is needed on how best to control
some contaminants (such as Crypto-
sporidtum), enough is known that most
experts believe significant risk reduction
can be achieved by ensuring high per-
formance of existing treatment facilities.
As water suppliers begin to voluntarily
assess and improve treatment facility
operations, EPA (with states) plans to
provide proven tools and assistance to
help systems achieve health risk
reductions.
EPA is currently on a court-ordered
schedule to propose a standard for arsenic by
November 1995.
3. Provide Technical
Assistance to Protect
Source Water and Help
Small Systems
An effective way to help ensure
the long term safety of drinking water is
to prevent pollution of lakes, rivers,
streams and ground water that serve as
sources of drinking water. This
common sense approach is known as
"source water protection."
The Safe Drinking Water Act
emphasizes monitoring and treatment
to protect drinking water safety.
However, protection based on moni-
toring and treatment alone is not suf-
ficient. Source water protection is an
important barrier to contamination and
can provide long term "insurance"
against costly future contamination.
Communities with clean and well-
protected source waters may be able to
reduce some types of monitoring or
avoid costly treatment without com-
promising public; health protection.
Communities can also avoid the need to
sink new water wells to replace contam-
inated wells. A single new well can cost
about $60,000 for very small com-
munity systems and hundreds of
thousands of dollars for larger systems.
Virtually all groups interested in
drinking water safety see a need for
stronger efforts to prevent pollution
from entering drinking water sources in
the first place, rather than relying solely
on water treatment to reduce health
threats.
Many states and communities
are promoting source water protection
right now, in the form of "wellhead
13
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Agenda Item 3: Provide Technical Assistance to Protect Source
Water and Help Small Systems
* EPA will sponsor a National Source, Water Protection Tele-Workshop,
in cooperation with states and tribes, communities, businesses,
public interest groups and others, which will provide thousands of *
communities with pollution prevention tools and information to \ /
protect their sources of drinking water. ,> , < '
£'''
/- f < /. <-
For states interested in the developmentof programs for '"
strengthening small system capability, EPA will provide on-site,
technical assistance information (including case study examples) on (
restructuring options, operator training, and appropriate water
treatment technologies.
* In addition, EPA will provide hands-on technical assistance,
including information on pollution prevention techniques^ to ,
businesses and industries that want to protect community drinking
water sources. ' ' ,
protection programs." Thousands of
communities, usually with help from
states, have made headway in ident-
ifying potential sources of contamin-
ation in areas near drinking water wells
and are working to solve and prevent
ground water contamination problems.
This concept can apply to surface water
supplies as well. EPA is encouraging
stronger watershed protection pro-
grams, using approaches available
under the federal Clean Water Act, to
protect surface waters that are used for
drinking water supplies. Source water
protection, for both ground water and
surface water, has the potential to offer
significant advantages to water systems
and ratepayers, and an invigorated
effort is needed to expand such
protection.
Efforts to improve the technical
and managerial capability of water
systems, particularly small systems, are
also "preventive" approaches for
assuring drinking water safety. Some of
the most seemingly intractable
problems in drinking water protection
are faced by small communities. These
problems are not new. A 1969 Com-
munity Water Supply Study found that
systems serving fewer than 500 people
had particular difficulty in meeting the
very basic standards established by the
U.S. Public Health Service. Although
many small systems provide excellent
service, a troubling number of systems
struggle to provide basic protection
against microbiological contamination.
14
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SfcKsiS^i^'fl&v^.'Vi.-a.iil&V-li^lvts&frS^
The variability and sheer number
of small systems has made uniform
safety a problem. Out of 57,000
community water systems in the U.S.,
50,000 - nearly 90% - serve fewer than
3,300 persons. An astonishing 17,000 -
- 30% serve fewer than 100 persons.
Two small systems out of five serve
unincorporated clusters of homes,
including mobile home parks and
homeowner associations. Despite the
large number of small systems, they
serve just 10 percent of households
nationally. Current safety standards
and water system practices are often
difficult to tailor to these various types
of small systems. In addition, many of
these systems, under current
conditions, may lack the financial,
managerial, and technical capability
necessary to ensure safe, affordable,
and high quality service.
New approaches are necessary in
many small communities to ensure
drinking water safety. Small
communities can work together in a
variety of ways to improve service and
reduce costs. For example, a number of
systems may be able to share the
service of a single trained operator.
Other options, depending on local
circumstances, include: internal
management improvements; informal
cooperation with other systems;
contract operation and maintenance;
bulk purchase of treated water; and
formation of management districts and
regional systems. New technologies also
hold promise. EPA has encouraged
these approaches, and some states are
making progress in helping small
systems improve their technical and
managerial capacity.
4. Reinvent Federal-
State Partnerships to
Improve Drinking Water
Safety
Strong state drinking water
programs are indispensable to ensuring
that public health is protected under
the Safe Drinking Water Act. All states
except Wyoming have "primacy" under
the Act to oversee implementation and
enforcement of safety regulations. If a
state's program is inadequate, the Act
provides that EPA carry out oversight.
In recent years, state resource shortfalls
have threatened the ability of some
states to carry out the drinking water
program, and EFA would be over-
whelmed trying alone to implement the
program in more than a few states.
The General Accounting Office
(GAO) reported in 1993 that "...it is
unclear whether the states are still
meeting the minimum requirements for
retaining primacy." GAO found that
"(d)rinking water program managers in
several states expressed concerns about
their ability to implement future regu-
lations, given their current budgetary
and implementation problems."21 GAO's
concern is echoed by EPA's independent
Inspector General, who has reported
that state program resource shortfalls
and EPA's own inability to "take over"
troubled state programs are among
the most serious weaknesses under
EPA's major environmental programs.
Funding shortfalls for state
drinking water programs may end up
15
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Agenda Item 4: Reinvent Federal-State Partnerships to Improve
Drinking Water Safety
In cooperation with states and other stakeholders, EPA will update .
existing federal guidance for state dMting wafer programs u&h #w?
goal of focusing implementation and enforcement activities on ,
regulations that provide the greatest risk reduction,, '.-'--.' ' 1
EPA will review current water testing (monitoring) requirements-jor
chemical contaminants with the goal of facilitating focal monitoring
flexibility, tailoring monitoring based on the quality of source witter,,
and encouraging the use of lower cost analytical techniques. -
Where water systems experience marginal or short
exceedances of safety standards, EPA will explore with states and
other stakeholders the use of longer term pollution prevention
approaches to reduce contamination of source water-, as an
alternative to water treatment - provided sensitive subpopujations
can be protected until prevention efforts succeed in meeting safety
standards. , , ' / ;
raising costs for systems. For example,
states can grant "waivers" to allow
community water systems to reduce
monitoring for certain contaminants
where the state determines that such
contaminants are unlikely to threaten
water supplies. For communities this
flexibility can save 50-90 percent of the
monitoring costs for some contam-
inants. The use of monitoring waivers
has been slow, however, because some
states lack the resources needed for
collecting information to assess threats
to local water supplies or reviewing
local assessments. This problem can be
addressed, in part, by further
streamlining and focusing monitoring
requirements toward areas of risk.
States also need funds for
technical assistance and enforcement.
which helps to promote compliance with
safety standards and reduce threats to
public health. Until states obtain
adequate funding for these and other
needs, states need flexibility to target
their resources to priority activities.
5. Invest In Community
Drinking Water
Facilities to Protect
Human Health
Sound drinking water infra-
structure is crucial to the provision of
safe drinking water. "Infrastructure"
includes the water treatment facility
itself, the distribution system, and other
associated pipes, tanks, storage
facilities, etc. Investments needed in
16
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drinking water facilities are con-
siderable - perhaps in the hundreds of
billions of dollars over the next two
decades. Only a portion of these
needs, $8.6 billion, is attributable to
investments necessary to meet current
federal drinking water safety
standards.** This does not include
future costs associated with treatment
for newly recognized threats, such as
Cryptosporidium, disinfection by-
products, and others.
EPA, in cooperation with states
and water suppliers, is conducting a
nationwide survey to determine national
drinking water infrastructure needs.
The survey examines how much money
Total Investment needs between 1984 and
2000 were estimated by the Congressional Budget
Office to be $130 billion (Public Works
Infrastructure: Policy Considerations for the 1980's.
Congressional Budget Office. April 1983.). An
update of this figure, accounting for (1) inflation; (2)
expenditures between 1984 and 1994 (based on
U.S. Commerce Department reports); and (3)
projections of future annual needs, yields a
projected total investment need of more than $200
billion for drinking water infrastructure.
These estimates are based on information
available at the time EPA issued regulations. New
evidence suggests that for some regulations (e.g.,
the Lead and Copper Rule) costs are substantially
less than anticipated, while for other rules (e.g., the
Surface Water Treatment Rule) costs are somewhat
higher.
systems need to invest to meet current
and anticipated drinking water safety
standards, to repla.ce arid repair aging
infrastructure, and where appropriate,
to restructure water systems. EPA
plans to publish the survey results in
early 1996.
Unlike oilier major infrastructure
needs that receive federal assistance -
- such as highways, harbors and
sewage treatment plants drinking
water infrastructure has received
relatively little federal support, and this
support has not been geared specifically
toward public health concerns.
President Clinton has requested a total
of $1.8 billion for fiscal years 1994,
1995 and 1996 for a Drinking Water
State Revolving Fund (DWSRF) - a
federally supported, state- operated loan
program to help communities invest in
public health protection. However, EPA
cannot distribute funds to states until
Congress appropriates these funds and
drinking water legislation authorizing
the DWSRF is passed by Congress.
17
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APPENDIX
SUBJECTS FOR STAKEHOLDER MEETINGS*
REGULATORY REASSESSMENT:
There is wide variability among
prospective drinking water regulations
in terms of the relative risk reductions
they will produce. In addition, EPA
does not believe it has the resources to
continue working on all regulations
currently required in a timely and high
quality fashion. EPA is seeking
comments from stakeholders in
developing a prioritized list of regulatory
activities. The priority list will be used
to identify which regulations can be
developed in the near term and which
are appropriate for a much longer time
frame for development. With this
information, EPA hopes to renegotiate
current court-ordered schedules and
more effectively direct federal, state, and
local resources.
SCIENTIFIC DATA NEEDS:
Up-to-date information and
quality models and methodologies are
essential to sound regulatory and
programmatic decision-making. They
form the foundation for the more visible
Agency actions and products. Because
data collection and analysis is resource
and time intensive, some trade-offs are
inevitable. EPA is seeking to identify
the most critical needs and other factors
which may merit consideration. This
subject area encompasses a wide range
of questions related to the development
of drinking water stemdards. Cost and
benefit assessments and data needs
related to source water protection will
also be discussed.
TREATMENT TECHNOLOGY:
Under the Safe Drinking Water
Act (SDWA), treatment technology is
important in the establishment of
National Primary Drinking Water
Standards and determining when
allowable flexibility in the form of
variances and exemptions for public
water systems is appropriate. EPA is
considering ways to improve treatment
technology detenininations and
associated issues. The Agency will seek
input on critical issues, including
criteria for determining best available
technologies and treatment technique
requirements; ways for EPA to promote
the development and application of
innovative technologies; and the need
for toxicological evaluation and
certification of treatment chemical and
system component safety.
*For Information on the Stakeholder Meetings, Call EPA's Safe
Drinking Water Hotline at 1-8OO/426-4791.
A-l
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HEALTH ASSESSMENT:
EPA is seeking stakeholder views
on revisiting the methodology for
determining Maximum Contaminant
Level Goals (MCLGs) for drinking water,
including the Agency's current policy of
setting zero goals for carcinogens. In
regulating drinking water contaminants
which may cause adverse health effects,
EPA sets non-enforceable MCLGs to
protect against these effects,
incorporating a margin of safety. EPA
also sets a Maximum Contaminant
Level (MCL), which is enforceable and
may be less stringent than the MCLG
depending on feasibility.
Several activities planned or
ongoing may improve the
characterization of the variability and
uncertainty associated with the risk
assessment for a contaminant. These
include noncancer risk assessment
methodologies such as the benchmark
approach and categorical regression
models, revision of the Cancer Risk
Assessment Guidelines, revision of the
relative source contribution policy,
evaluation of risk assessment methods
for chemical mixtures and development
of a risk characterization policy.
ANALYTICAL METHODS:
EPA is considering priorities for
enhancing the analytical methods
approval process and laboratory
certification program within the context
of developing and implementing
drinking water regulations. The Agency
is seeking stakeholders' suggestions for
making improvements while assuring
the comparability and quality of
measurement data. Specific issues to
be addressed include: streamlining the
drinking water methods approval
process, including the use of
performance-based methods;
approaches for standardizing the
detection and quantification of
contaminants in water; laboratory
certification; opportunities for
integrating methods across Agency
water programs; and the relationship to
methods organizations inside and
outside of the Agency.
SOURCE WATER PROTECTION:
EPA is planning a National
Source Water Protection Workshop in
1996 which will provide communities
with tools and information to enable
them to protect their sources of
drinking water. The tele-workshop will
be targeted to communities which have
delineated their source water protection
areas and carried out source
identification, and will assist such
communities in moving to source
management. EPA is seeking to work
with states, communities, interest
groups and business leaders to
maximize participation in the tele-
workshop.
EPA is also seeking stakeholder
input on the development of source
water protection approaches for
communities that rely on surface water
and the development of a new consumer
information provision to inform
ratepayers about local water quality and
source water protection.
SMALL SYSTEMS CAPACITY
BUILDING:
EPA recognizes the need to
develop options and priorities for
building small system capacity,
including in the areas of management
and operations, technology, and
financing. The Agency is seeking
suggestions on how best to focus and
follow-up on current activities relative to
voluntary state viability program
A-2
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development and small systems
restructuring. EPA is also seeking
ideas and viewpoints on issues
associated with technical assistance
and training for small systems* as well
as how best to identify and promote Use
of appropriate small systems
technologies.
FOCUSJ3VG AND IMPROVING
IMPLEMENTATION:
This subject encompasses several
topics. EPA is generally seeking
stakeholder views on which of these of
other implementation activities the
Agency should undertake. Where the
Agency plans to carry out a particular
activity, as in reviewing the State
Drinking Water Program Priorities
Guidance, stakeholder views on
appropriate approaches are also being
sought. The topics include the
following:
Review of State drinking water
program priorities guidance:
Recognizing the limited resources
that states have to keep pace with
expanding federal drinking water
program requirements, EPA issued
guidance in June 1992 to focus EPA
and state resources on the highest
priorities first and allow states extra
time to build resources in order to fully
implement the program. The priority
scheme was to be effective between
1993 and 1998, during which time
states are expected to aggressively
develop adequate funding to oversee the
entire Public Water Supply Supervision
(PWSS) program. The guidance does
not change or defer statutory or
regulatory requirements for EPA, state
agencies, or public water systems.
States have used the guidance
successfully in addressing their most
important implementation, enforcement
and resource challenges. EPA believes
that it is time to re-examine this
guidance, based upon the experience
gained over the past two years, and
determine if any changes are needed to
more appropriately focus resources on
the highest risks flirst The Agency also
needs to determine how to include new
requirements in the priority scheme.
Revising Chemical Monitoring
Requirements and Defining Source
Water Protection as Best Available
Technology:
Public water' systems are
required to monitor for 66 different
Inorganic (e.g., mercury), synthetic
organic (e.g., atrazine) and volatile
organic compounds (e.g., benzene)
found in drinking water. Costs to collect
and analyze these chemicals can be
Several thousands of dollars per year,
which can be beyond the resource
capacities for small systems. Several
statutory (Chafee-Lautenberg
Amendment) and regulatory (e.g.,
grandfathering data, compositing, state-
approved waivers) provisions have
provided flexibility to systems to reduce
or forego monitoring for at least some
chemicals. EPA believes it would be
appropriate to consider other revisions
to chemical monitoring requirements
by, for example, targeting systems at
risk of contamination, targeting
vulnerable time periods and allowing
States greater flexibility to integrate
source water protection efforts. EPA
also believes it might be useful to
consider regulatory changes to allow
water systems to use source water
protection as an alternative form of
treatment for certain contaminants
under limited conditions, provided such
an alternative provides equivalent
health protection.
A-3
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Other Revisions to Strengthen
Enforcement and Implementation:
Recognizing the limited resources
in the drinking water program, EPA is
interested in hearing ideas to further
strengthen the public health protection
provided by the Safe Drinking Water Act
and current regulations while
streamlining the program.
These activities could take the
form of outreach, technical assistance
and capacity building, or use of
authorities provided under other
environmental statutes. For example,
some potential activities in this area
might include special health notification
for serious drinking water
contamination, particularly for sensitive
subpopulations; additional joint
state/EPA efforts to develop state
capacity to implement and enforce the
drinking water program; and
streamlining and strengthening EPA's
ability to gather information from
drinking water systems (particularly in
cases where contamination is suspected
or where a system is required to
monitor on a greatly reduced basis).
The activities in this area would be
designed to ensure greater public health
protection and would link to the actions
being proposed in other areas (e.g.,
regulatory realignment, review of
priority guidance and greater emphasis
on source water protection.)
A-4
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RegulationsReport to Congress, U.S. Environmental Protection Agency. September 1993.
3 . Water: A National Priority, The Roper Organization Inc., conducted for the National Geographic
Society. November 1993.
4 . Consumer Attitude Survey on Water Quality Issues, American Water Works Association Research
Foundation. October 1993.
5. Bottled Water in the U.S., Beverage Marketing Corporation. 1994.
6 . Reducing Risk: Setting Priorities and Strategies for Environmental Protection. U.S. Environmental
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344:1360-1361. 1994.
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Potable Water Systems," Rogers, J., et.al., Applied Environmental Microbiology, 60:1842-1851. 1994.
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Agriculture, Economic Research Service. Agricultural Economic Report (AER) 535, and earlier reports in
this series. Washington, D.C.
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Protection, Water Science and Technology Board, National Research Council. 1986.
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Agriculture. February 1993.
-------
19 . National Water Quality Inventory - 1992 Report to Congress, U.S. Environmental Protection Agency.
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2 0 . 1992 National Survey of Pesticides In Drinking Water Wells, Phase II Report. U.S. Environmental
Protection Agency. January 1992. (Estimate Includes bpth public water systems and domestic wells.)
21. Drinking Water Program States Face Increased, Difficulties in Meeting Basic. Requirements, General
Accounting Office. June 1993.
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