Condition of Lakes in the United States
Understanding the Charts
The charts below show the overall condition of U.S. lake acres. They also show the most common types of pollution in lakes and the major sources of this pollution.
Top Problems
Here is a rundown on the major types of pollution:
- Too many nutrients refer to excess plant food such as nitrogen and phosphorus.
- Metals include iron, cadmium, and mercury.
- Soil moving into water is also known as “siltation.”
- Total dissolved solids include salts and minerals, which dissolve in water.
- Substances that take oxygen from water include organic matter (rotting animal and plant material).
- Too much algae refer to a form of aquatic plant.
- Pesticides are chemicals used to kill pests such as weeds and insects.
Major Sources of Pollution
Three categories under “Major Sources of Pollution” may need an explanation:
- Changes made to lake include dredging (scooping sediment from the lake bottom) and the construction of dams.
- Nonpoint pollution comes from many points on the land. It includes soil erosion and runoff water.
- Land disposal includes landfills and the disposal of wastewater and sludge on land.
Where Do These Numbers Come From?
The U.S. Environmental Protection Agency collected this information by studying the water quality of 17.3 million acres of lakes and ponds—about 43 percent of the total acres of lakes and ponds in the United States.
By the way, an acre is a little bit smaller than the size of a football field.
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