United States
Environmental Protection
Agency
Office of Water
(4606)
EPA816-F-00-002
February 2000
vvEPA
Drinking Wafer: Past, Present,
and Future
This fact sheet contains highlights from a target report, "25 Years of the Safe Drinking
Water Act: History and Trends." Please refer to the full report for details and references.
You may order a copy of the report, as well as many other EPA drinking water documents, by
calling the Safe Drinking Water Hotline at (800) 426-4791, or you may view the report
online at
http://www. epa. gov/safewater/sdwa25/sdwa. html
Civilizations have faced the challenge of obtaining safe drinking water for thousands of years. As
a global society, we have learned a great deal about drinking water quality. However, we still have
much to learn about the health effects of drinking water contaminants, the testing and treatment
technologies required to detect and remove contariiinants, and ways to protect our water sources
from contamination.
During the 1800s, scientists began to gain an understanding of the sources and effects of drinking
water contaminants, especially those that were not visible to the naked eye. By the early 1900s,
engineers had developed techniques such as filtration and chlorination to prevent waterborne
microbes from causing disease. .
Highlights of the
Safe Drinking Water Act
Authorizes EPA to set enforceable health standards for
contaminants in drinking water
Requires public notification of water systems' violations
and annual reports to customers on contaminants found
in their drinking water
Establishes a federal-state partnership for regulation
enforcement
Includes provisions specifically designed to protect
underground sources of drinking water
Requires disinfection of surface water and, as necessary,
ground water used for drinking water
Requires filtration of all surface water supplies, except
those with pristine, protected sources
Establishes a multi-billion dollar state revolving loan
fund for water system upgrades
Requires an assessment of the vulnerability of all
drinking water sources to contamination
Federal regulation of drinking water quality began in 1914,
when the U.S. Public Health Service set standards for
some disease-causing microbes. These standards were
revised and expanded and eventually, with minor modifica-
tions, all 5D states adopted the final 1962 Public Health
Service standards either as regulations or as guidelines.
By the latei 1960s, man-made chemicals began to have a
noticeably; negative impact on the environment. Health
concerns spurred the federal government to conduct several
studies on the nation's water supplies which showed that
many chemicals were present in treated drinking water.
Increased awareness of environmental and health problems
in the early 1970s eventually led to the passage of several
federal laws, one of which was the Safe Drinking Water
Act (SDWA) of 1974. SDWA is administered by the U.S.
Environmental Protection Agency (EPA) and its partners.
SDWA aims to ensure that public water systems meet
national standards that protect consumers from the harmful
effects of contaminants in drinking water.
SDWA requires EPA to regulate contaminants that present
health rislqs and are known to, or are likely to, occur in
public drinking water supplies. For each contaminant
requiring regulation, EPA sets a legal limit on the amount of the contaminant allowed in drinking
water (states may also set limits that are at least as: strict as EPA's). Since 1974, the number of
contaminants regulated under SDWA has quadrupled [see figure 1 next page].
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If a system violates EPA or state
regulations, it must notify the
public. States are required to
report violations to EPA's
database, the Safe Drinking
Water Information System
(SDWIS). This fact sheet
focuses mostly on community
water systems (systems that
provide drinking water to the
same people year-round),
because they are subject to all
SDWA regulations and serve
most Americans. The population
being served by community
water systems with no violations
of health-based standards has
increased steadily from 83
percent in 1994 to 89 percent in 1998 [see figure 2].
Compliance Trends
One way to gauge whether the quality of our nation's drinking
water lias improved under SDWA is to examine water systems'
compliance With federal regulations. Evaluations of the
quality of compliance data in SDWIS have shown that a
significant number of violations have not been reported to
SDWIS. EPA and its partners are correcting these data
deficiencies. While deficiencies make it difficult to look at
historical compliance trends using SDWIS data, this is the
best source of drinking water data that exists on a nationwide
basis. Therefore, we present the following examples of
compliance trends, recognizing that the actual number of
systems in violation may be higher than shown.
Total Coliform: The Most Frequently
Violated Regulation
Figure 1. Number of Contaminants Regulated Under the
Safe Drinking Water Act, by Contaminant Type
Radionuclides
Microbes
Organic Chemicals
Inorganic Chemicals
Figure 2. Percent of Population Served by
Community Water Systems With
No Violations of Health-Based Standards
1994
1995
1996
1997
1998
Coli forms are a group of bacteria that are common in both the environment and the digestive tracts j
of humans and animals. Most of these bacteria are harmless; however, their presence in water at 1
any level indicates that disease-causing microbes may also be in the water. I
Since 1980, over 80 percent of all community water systems with any health-based violation had a
violation for total coliform. However, the number of systems with total coliform violations has
decreased fairly steadily since 1980, by about 200 systems per year.
System Size Affects Violation Trends
Community water systems of all sizes have generally followed the same decreasing trend in
violations since 1980, except for a period in the early 1990s when systems of all sizes struggled to
comply with several new regulations [see figure 3]. In recent years, it appears that the gap between
the percentage of small, medium, large and very large systems with violations has been closing.
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Figure 3. Percent of Community Water Systems with
Any Violations, by System Size
70%
60%
50%
40%
30%
20%
10%
0%
Very Small (25-500)
Small (501-3,300)
However, very small
systems are still almost 50
percent more likely to
violate regulations than
all other system sizes.
Very small systems
generally have the least
amount of resources
necessary to maintain and
upgrade equipment.
Waterborne
Disease
Outbreaks
Another way to look at the
quality of our nation's
drinking water is to
examine whether the
number of people
becoming ill from drinking contaminated water has decreased over the last 25 years. EPA and the
Centers for Disease Control and Prevention (CDCj) believe that the vast majority of waterborne
disease outbreaks are never identified or reported.1 For this reason, EPA and CDC have been
working together to gather as much data as possible on waterborne disease outbreaks across the
country. Although the number of reported outbreaks in the U.S. has generally declined since the
early 1980s [see figure 4], some of the more recent outbreaks have been very serious, causing
numerous people to become ill and, in some cases;, even causing death.
In the last ten years, EPA has taken several actions to minimize outbreaks of waterborne disease by
requiring disinfection of most surface water supplies (lakes, rivers, and reservoks) and frequent
testing for microbes. In 2000, EPA plans to propose a regulation that will require protection and
treatment of ground water sources.
Medium (3,301-10,000)
Large (10,001-100,000)
Very Large (over 100,000)
Figure 4. Number of Waterborne Disease Outbreaks in Cqmmunity
Water Systems and Their Causitive Agents (1974-1996)
The Cost of
Safe Drinking
Water
The cost of tap water is
rising as suppliers
maintain and upgrade
aging treatment plants,
comply with more
regulations, and serve a
growing population. In
most cases, these increas-
ing costs have caused
water suppliers to raise
their water rates. How-
ever, despite rate in-
creases, water is generally
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still a bargain when compared with other utilities such as electricity and telephone service. It is
also important to recognize that, due to historic underpricing, the rates most water systems
charge their customers do not reflect the true cost of treating and delivering drinking water.
Treatment versus Prevention
Over the years, the number of water systems treating their water has increased [see figure 5].
Although treatment can be very effective at removing contaminants from drinking water, it can
sometimes be expensive.
Also, removing contami-
nants from drinking water
does not necessarily remove
them from the environment
(e.g., contaminants removed
from water are often-
disposed on land or released
into the air). A more
environmentally sustainable
solution to drinking water
contamination is to prevent
pollutants from reaching
drinking water sources in
the first place. Several
programs that protect
source water exist under
SDWA and other environ-
mental laws.
Figure 5. Percentage of Community Water Systems Providing
Any Treatment, by Population Served
100%
60% -
40% -
20% -
0%
0-100
101-500
501-1,000
1,001-3,300
3,301-10,000
1976
1.982
1986
1995
Challenges Ahead
While tremendous progress has been made over the last quarter century in improving the testing,
treatment, source protection, and provision of drinking water to the public, numerous challenges
remain:
* More drinking water health information will need to be provided in a timely fashion to consum-
ers who are most vulnerable to contaminants. This is especially important as cancer survivors
and HIV/AIDS patients increase in number, and the elderly make up a growing percentage of the
population.
• The public and private sectors must work together to more effectively and efficiently conduct
sound scientific research in order to continue learning about the health effects of known contami-
nants, and to begin studying emerging contaminants.
• Tap water must be conserved and its sources protected in order to lessen the negative impacts
that trends in increasing population, urbanization and development may have on the future
availability and quality of drinking water.
• Consumers must recognize that high quality tap water comes at a price, but one that can be
significantly less than alternatives such as bottled water.
• Consumers must also recognize that their actions affect the quality of their source water and the
level of treatment that is required to allow safe drinking water to flow from their taps.
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