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Woman holding a glass of water.

You might not give much thought to water or how it gets to you. You just turn on the faucet and there it is.

Do you ever wonder how it flows from your faucet? And have you ever stopped to think about whether or not it is clean? For most people in the United States, this isn’t an issue. You can usually fill up a glass from the tap and drink it down without concern that it might make you sick.

Your water can come from a lake, a river, a reservoir, or a well. Wherever it comes from, it starts from a watershed. A watershed is the land area that drains into a single body of water (like a lake) or to groundwater (the fresh water found under the Earth’s surface that supplies wells and springs). Everything that happens in the watershed, and from the water source to your tap, affects the quality of your water. In order to have clean water to drink, we must keep the watershed clean.

The following things can make your water dirty and unsafe for drinking and/or swimming:

  • Natural events. Floods, hurricanes, earthquakes, or landslides can cause dirt to get into our drinking water.
  • Pesticides and fertilizers. Americans use 67 million pounds of pesticides to keep our lawns free of weeds and bugs. These chemicals may be washed into our water supply.
  • Lead pipes. Lead can cause health problems for people, especially babies, children, and pregnant women. Lead gets into drinking water from the pipes that carry the water in some cities and older homes.
  • Animal or human waste.  If animal or human feces (say: fee-sees) gets into the drinking water, you could get very sick.
  • Littering. Some things, like batteries, should not be thrown into the trash. They should be recycled. Otherwise, the chemicals in the batteries can get into the watershed. Other things that should not be flushed down the toilet, dumped down the drain, or just put out with the regular trash are electronics, paints, cleaners, unused medicines, motor oil, and certain lightbulbs.
  • Algae blooms. Too much harmful algae (say: AL-jay) in freshwater or seawater can make beaches unsafe for people.  Algae are very small plants that are usually in the water, made up of one cell, and lack true stems, roots, and leaves.
  • Spills and accidents. Industrial accidents like oil spills can pollute our water sources and harm fish and wildlife.

Drinking dirty water can hurt your health. Learn more about the health effects of polluted water. You can also learn more about how to protect yourself from water pollution! 

A spigget pouring water into a glass.

Source: U.S. Environmental Protection Agency

Here are some fun facts about water. Read through them and then test yourself by taking a quiz! Click on the question to view/hide the answers.

1. How long can a person live without food?

A person can live without food for more than a month.

2. How long can a person live without water?

A person can live without water for only about one week, depending upon conditions.

3. How much of the human body is water?

About 66 percent of the human body is water.

4. How much of the earth’s surface is water?

About 80 percent of the earth’s surface is water.

5. How much water must a person consume per day to stay healthy?

A person must have about 2.5 quarts of water each day. This includes both water you drink and water in food (like fruits and vegetables).

6. Of all the earth’s water, how much is ocean or seas?

97 percent of the earth’s water is ocean or seas.

7. How much of the world’s water is frozen?

Of all the water on earth, about 2 percent is frozen.

8. How much of the earth’s water is good for drinking?

Only 1 percent of the earth’s water is good for drinking.

9. Is it possible for me to drink water that was part of the dinosaur era?

Yes. Water is recycled over and over again.

10. What is the most common substance found on earth?

Water is the most common substance on earth.

11. How much water does the average house use during a year?

Each family uses over 100,000 gallons of water a year (indoors and outside).

12. How much water does each person use per day (on average)?

Each person uses over 100 gallons of water every day (all uses).

13. How much water is used to flush a toilet?

A flush can use up to seven gallons of water.

14. How much water is used in the average five-minute shower?

A five minute shower uses about 15-25 gallons of water.

15. How much water is used on the average for an automatic dishwasher?

A dishwasher can use up to 12 gallons of water per load.

16. On average, how much water is used to wash dishes by hand?

Washing dishes by hand takes about 9-20 gallons of water.


Content last reviewed July 20, 2010
Page last updated October 31, 2013