Aquifers

An aquifer is an underground layer of rock, sand, or gravel that holds water. Water fills the tiny spaces between the grains of rock, like water in a sponge. Aquifers supply water to wells and springs. They are one of the most important sources of fresh water on the planet.

How Aquifers Work

When rain falls, some of it soaks into the ground and slowly trickles down into an aquifer. This process is called recharge. People drill wells into aquifers to pump water up to the surface. Some aquifers are small, while others stretch under entire states. The Ogallala Aquifer under the Great Plains is one of the largest in the world.

Protecting Our Aquifers

Aquifers can be polluted if chemicals from farms or factories seep into the ground. Once an aquifer is contaminated, it is very hard to clean. Some aquifers are being drained faster than rain can refill them. Using water wisely and preventing pollution helps keep aquifers healthy for future generations.

Fun Facts

• The Ogallala Aquifer holds enough water to cover the entire United States in about 1.5 feet of water!
• Some aquifers hold water that fell as rain more than 10,000 years ago.
• About 2 billion people worldwide depend on groundwater from aquifers for their daily water supply.

Did You Know?

The Great Artesian Basin in Australia is one of the largest aquifers in the world, stretching under nearly one-quarter of the entire continent!