&EPA
United States
Environmental Protection
Agency
Office of Water (45G3F)'
Washington, DC 20460
EPA841-F-95-G1G
December 1995
Water Quality Conditions in the United States
A Profile from the 1994 National Water Quality Inventory
Report to Congress
Findings
Based on the latest information reported to EPA by States,
Tribes, and other jurisdictions with water quality responsibili-
ties, about 40% of the Nation's surveyed rivers, lakes, and
estuaries are not clean enough for basic uses such as fishing
or swimming. The results are consistent with data last
reported in 1992 and show that rnore work is needed if
waters are to be made clean and healthy in all communities.;
These results are based on water quality surveys conducted in
1992 and 1993. Nationwide, 1 7% of rivers, 42% of lakes,
and 78% of estuaries were surveyed.
Polluted runoff from rainstorms and snowmelt is the leading
cause of impairment in rivers, lakes, and estuaries. For rivers
and lakes, runoff from agricultural lands is the biggest source
of pollution. Storm sewers and urban runoff are the leading
sources of pollution in estuaries. Bacteria, which can cause
illnesses in swimmers and others involved in water-contact
sports, are the rnost common pollutants impacting rivers.
Nutrients, such as phosphates and nitrates, are the most
often reported pollutant in Jakes and estuaries. In excess,
nutrients can create a chain of impacts that include algal
blooms, fish kills, foul odors, and weed growth.
I =
Background
Water quality surveys are conducted to determine a "
waterbody's overall health, including whether or not basic
uses are being met. States, Tribes, or other jurisdictions define
appropriate uses for a waterbody and incorporate these uses
into water quaNty standards that are approved by EPA.
States and other jurisdictions conductwater quality surveys
and report the findings to EPA every 2 years. EPA then
prepares a biennial Report to Congress, which represents the
most complete and up-to-date snapshot of water quality
conditions around the country. This report is the tenth in a
series of reports that have been prepared and submitted to
Congress since 1975. .
About 40% of the Nation's surveyed
rivers, lakes, and estuaries are not clean
enough to meet basic uses such
as fishing or swimming.
How Our Waters Are Used
Aquatic Life
Fish Consumption
Shellfishing
Swimming
Other Recreational Uses
Drinking Water
ssgair -Agriculture
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Leading Causes
! of Pollution i
1
2
3
4
5
; Bacteria
Siltation
', Nutrients
! Oxygen-Depleting
Substances
Metals
About 36% of surveyed rivers are
impaired - about the equivalent
of 100 Mississippi Rivers.
The U.S. has 3.5 million miles of
rivers and streams.
Surveys were conducted on
615,806 miles, or 17%.
Leading Sources
' of Pollution
1
2
3
4
5
Agriculture
Municipal Sewage
Treatment Plants
Hydrologic/Habitat
Modification
Urban Runoff/
Storm Sewers
Resource Extraction
Leading Causes
of Pollution
1
2
3
4
5
Nutrients
Siltation
Oxygen-Depleting
Substances
Metals
Suspended Solids
About 37% of surveyed lakes are
impaired - about the equivalent
of 6 Great Salt Lakes.
The U.S. has 41 million acres of lakes.
Surveys were conducted on about
17 million acres, or 42%.*
*Excludes the Great Lakes.
Leading Sources
of Pollution
1
2
3
' 4
5
Agriculture
Municipal Sewage
Treatment Plants
Urban Runoff/ '
Storm Sewers
Unspecified
Nonpoint Sources
Hydrologic/Habitat
Modification
Leading Causes
of Pollution
Nutrients
Bacteria
Oxygen-Depleting
Substances
Habitat Alterations
Oil and Grease
M Estuary Profile
• About 37% of surveyed estuaries
are impaired - about the equiva-
lent of 3 Chesapeake Bays.
• The U.S. has 34,400 square miles
of estuaries.*
• Surveys were conducted on about
27,000 square miles, or 78%.
*Excludes an unknown number of estuaries in Alaska.
Leading'Sources
of Pollution
1
2
3
4
5
Urban Runoff/
Storm Sewers
Municipal Sewage
Treatment Plants
Agriculture
Industrial Point
Sources
Petroleum Activities
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