How does the water get underground?
The Earth’s surface is permeable, which means that it takes in water in like a sponge. Water gets into an aquifer from the land surface. Typically, precipitation falling onto the Earth’s surface soaks into the ground and flows down to the water table.

How long does water spend underground?
Some drops of water spend only a couple months as groundwater, but other water drops may spend 10,000 years underground!

How does it get out of the ground?
Water often leaves the ground by seeping into the ocean. People pump groundwater out of the ground through wells.