Skip to main content
U.S. flag

An official website of the United States government

Water Quality

What is in that water that you just drank? Is it just hydrogen and oxygen atoms? Is it safe for drinking? All water is of a certain "quality" (and you can't tell by just looking), but what does "water quality" really mean? 

Filter Total Items: 45

Downloadable Products

The U.S. Geological Survey (USGS) offers you the most comprehensive information about the natural water cycle anywhere, and, our information is available in many languages. Here you can download our water cycle diagrams as well as other educational products to assist you in the classroom or on your own learning adventure!
link

Downloadable Products

The U.S. Geological Survey (USGS) offers you the most comprehensive information about the natural water cycle anywhere, and, our information is available in many languages. Here you can download our water cycle diagrams as well as other educational products to assist you in the classroom or on your own learning adventure!
Learn More

pH and Water

pH is a measure of how acidic/basic water is. The range goes from 0 to 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base. The pH of water is a very important measurement concerning water quality.
link

pH and Water

pH is a measure of how acidic/basic water is. The range goes from 0 to 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base. The pH of water is a very important measurement concerning water quality.
Learn More

Water Quality Questions & Answers

What is in that water that you just drank? Is it just hydrogen and oxygen atoms? Is it safe for drinking? All water is of a certain "quality" (and you can't tell by just looking), but what does "water quality" really mean? It can be thought of as a measure of the suitability of water for a particular use based on selected physical, chemical, and biological characteristics. Here at the Water...
link

Water Quality Questions & Answers

What is in that water that you just drank? Is it just hydrogen and oxygen atoms? Is it safe for drinking? All water is of a certain "quality" (and you can't tell by just looking), but what does "water quality" really mean? It can be thought of as a measure of the suitability of water for a particular use based on selected physical, chemical, and biological characteristics. Here at the Water...
Learn More

Desalination

Humans cannot drink saline water but saline water can be made into freshwater, for which there are many uses. The process is called "desalination", and it is being used more and more around the world to provide people with needed freshwater.
link

Desalination

Humans cannot drink saline water but saline water can be made into freshwater, for which there are many uses. The process is called "desalination", and it is being used more and more around the world to provide people with needed freshwater.
Learn More

Acid Rain and Water

Depending on where you live, maybe you've heard of acid rain. Now, acid rain is not pure acid falling from the sky, but rather it is rainfall or atmospheric moisture that has been mixed with elements and gases that have caused the moisture to become more acidic than normal. Pure water has a pH of 7, and, generally, rainfall is somewhat on the acidic side (a bit less than 6). But, acid rain can...
link

Acid Rain and Water

Depending on where you live, maybe you've heard of acid rain. Now, acid rain is not pure acid falling from the sky, but rather it is rainfall or atmospheric moisture that has been mixed with elements and gases that have caused the moisture to become more acidic than normal. Pure water has a pH of 7, and, generally, rainfall is somewhat on the acidic side (a bit less than 6). But, acid rain can...
Learn More

The Water Science School -- What We Offer

The U.S. Geological Survey's Water Science School Where anyone of any age can learn all about water.
link

The Water Science School -- What We Offer

The U.S. Geological Survey's Water Science School Where anyone of any age can learn all about water.
Learn More

Water Science Photo Galleries

Learn about water using pictures
link

Water Science Photo Galleries

Learn about water using pictures
Learn More

Water Q&A: How is sewage and wastewater treated?

Learn about different sewage and wastewater treatment methods.
link

Water Q&A: How is sewage and wastewater treated?

Learn about different sewage and wastewater treatment methods.
Learn More

Water Q&As: How does our swimming pool stay so clean?

Learn about different methods to keep swimming pool water clean and safe.
link

Water Q&As: How does our swimming pool stay so clean?

Learn about different methods to keep swimming pool water clean and safe.
Learn More

Water Q&As: Why does my water smell like rotten eggs?

Learn about the causes of bad-smelling water and what you can do about it.
link

Water Q&As: Why does my water smell like rotten eggs?

Learn about the causes of bad-smelling water and what you can do about it.
Learn More

Water Q&A: What causes fish kills?

Find out more about the causes of fish kills, including dissolved oxygen and toxins.
link

Water Q&A: What causes fish kills?

Find out more about the causes of fish kills, including dissolved oxygen and toxins.
Learn More

Water Q&A: Is groundwater always clean?

Learn about groundwater quality and potential contaminants .
link

Water Q&A: Is groundwater always clean?

Learn about groundwater quality and potential contaminants .
Learn More
Was this page helpful?