Texas Commission on Environmental Quality (TCEQ). Class C Water License Exam

Which of the following represents a source of groundwater?

1. Reservoir

2. Aquifer

3. Stream

4. Pond

The correct answer is: Aquifer

An aquifer represents a source of groundwater because it is a geological formation that can store and transmit significant amounts of water, allowing it to be extracted for various uses, such as drinking water and irrigation. Aquifers are typically composed of permeable materials, like sand or gravel, which enable water to flow through them, and they can be found below the Earth's surface, where they collect rainwater and surface water that percolates downwards. In contrast, a reservoir is a body of water, usually created by damming a river, that holds surface water rather than groundwater. Streams are surface water bodies, typically flowing continuously, and they do not serve as a groundwater source. Similarly, a pond is a smaller, still body of water that primarily holds surface water. Therefore, the characteristic of storing and supplying water underground specifically identifies aquifers as sources of groundwater.