Groundwater stays at the same temperature all year so it can be used to heat houses in winter and cool them in summer. In some parts of the world where little rain falls, groundwater is the only source of water. Without it no one could live in those places, and no plants would grow. Because of water quality's importance to the health of humans and ecosystems, federal and state governments and water users have focused attention in recent years on cleaning up polluted groundwater. Scientists study how groundwater is polluted, including how below-ground differences in chemical composition as well as biological and chemical reactions affect the pollution.
Science is constructed of facts as a house is of stones.
But a collection of facts is no more a science than a heap of stones is a house. See if you can find groundwater. At the beach begin digging, and before you go very far water will begin to pool in the bottom of the hole. You have uncovered groundwater. Find out how fast water moves through different kinds of soil.