The Earths Water Cycle
Water never stops moving. Snow and rain fall to the earth from clouds. The rain and melted snow run downhill into rivers and lakes, sometimes crashing over waterfalls. Eventually the water flows into the ocean.
During evaporation, the water turns from liquid into gas, and moves from oceans and lakes into the atmosphere where it forms clouds. Then the cycle begins all over again.
Water Treatment Cycle
Coagulation
This removes dirt and other particles suspended in water. Alum and other chemicals are added to water to form tiny sticky particles called "floc" which attract the dirt particles. The combined weight of the dirt and the alum (floc) become heavy enough to sink to the bottom during sedimentation.
Filtration
The water passes through filters, some made of layers of sand, gravel, and charcoal that help remove even smaller particles.
Disinfection
A small amount of chlorine is added or some other disinfection method is used to kill any bacteria or microorganisims that may be in the water.
Storage
Water is placed in a closed tank or reservoir in order for disinfection to take place. The water then flows through pipes to homes and businesses in the community.
