After the treatment of sedimentation, coagulation-flocculation, filtration, and disinfection, the water should be free of most contaminants. Discuss the importance of water as concerns the human body. One out of five people lacks a clean water supply. List the three major categories of water consumers in the world. Explain how the zone of saturation develops.
Rain falls to the earth and is pulled by gravity through spaces in the soil.
When the water reaches an impermeable layer of rock, the water stops moving.