Water Science School
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? Water full of dirt and grime might work fine for a tomato plant but would you want to drink it? Water quality can be thought of as a measure of the suitability of water for a particular use based on selected physical, chemical, and biological characteristics
All Water Quality Science Topics
View a list of all of our science topics about water quality.
Learn moreWater Quality Data for the Nation
The USGS National Water Information System (NWIS) contains extensive water-quality data, both real-time and historical, for the nation.
Get WQ DataBrowse Water Quality science related to:
Water Quality Information by Topic
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? Water full of dirt and grime might work fine for a tomato plant but would you want to drink it? Water quality can be thought of as a measure of the suitability of water for...
Water Science Photo Galleries
Learn about water using pictures
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.
Water as Acid Rain
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...
La Ciencia del Agua para Escuelas
La Ciencia del Agua para Escuelas
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...
Groundwater Quality
Even though the ground is an excellent mechanism for filtering out particulate matter, such as leaves, soil, and bugs, dissolved chemicals and gases can still occur in large enough concentrations in groundwater to cause problems.
Mercury Contamination of Aquatic Environments
Mercury has got to be one of the most fascinating elements around. In looking at the bubbles of bright silver sitting on a flat surface, it is easy to see why mercury is also called "quicksilver." Mercury is the only metal that exists in liquid form. It may act somewhat like water, but it is nothing at all like water, especially in the potential harmful effects it can have on humans and...
Water Quality Information by Topic
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? Water full of dirt and grime might work fine for a tomato plant but would you want to drink it? Water quality can be thought of as a measure of the suitability of water for...
Water Science Activity Center
This is the interactive section of our site where you can answer challenge questions, participate in opinion surveys about water issues, and take true/false quizzes.
A Visit to a Wastewater Treatment Plant
Have you ever wondered what happens to that water and waste after you flush? How about after you pull the plug on your tub? The modern wastewater-treatment plant employs basic physics and high technology to purify the dirtiest of water so it can go back into the environment as a member in good standing of the water cycle.
Wastewater Treatment Water Use
Wastewater is used water. It includes substances such as human waste, food scraps, oils, soaps and chemicals. In homes, this includes water from sinks, showers, bathtubs, toilets, washing machines and dishwashers. Businesses and industries also contribute their share of used water that must be cleaned.
Urbanization and Water Quality
There's no end to the effects that urbanization can have on water bodies. Millions of people; landscape manipulation; waste material; dumping of chemicals and fertilizers; withdrawing water for peoples' uses. As you expect, urbanization rarely improves water quality, but in order to prevent problems, one needs to understand how urbanization affects the local waters.