Condition of Rivers and
Streams in the United States
Understanding the Charts
The charts below show the overall condition of U.S. river miles. They also show the most common types of pollution in rivers and the major sources of this pollution.
Top Problems
Here is a rundown on the major types of pollution:
- Bacteria are microscopic organisms that can get people sick.
- Soil moving into water is also known as “siltation.”
- Habitat changes include changes to streambanks and drainage of wetlands.
- Substances that take oxygen from water include organic matter (rotting animal and plant material).
- Too many nutrients refer to excess plant food such as nitrogen and phosphorus.
- Water temperature changes can happen when water is used to cool industrial plants.
- Metals include iron, cadmium, and mercury.
- Water flow changes can happen during a drought or when water is released from a dam.
Major Sources of Pollution
Two categories under “Major Sources of Pollution” may need an explanation:
- Changes made to river include the construction of dams, straightening of rivers, and dredging (scooping sediment from the river bottom).
- Habitat changes include the removal of vegetation along streambanks.
Where Do These Numbers Come From?
The U.S. Environmental Protection Agency collected this information by studying the water quality of 699,946 miles of rivers and streams—about 19 percent of the total miles of rivers and streams in the United States.
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