Water Treatment Process

Water in lakes and rivers often contains impurities. The water can also contain bacteria and other microbiological organisms that can cause sickness and disease. So water from most surface water must be cleaned before is can be consumed. That's the work of a wastewater treatment plant.

How does the dirty water you flush down a toilet get cleaned safely before it's released to the environment? How water is treated and delivered to your home as water that is safe to drink. Follow a drop of water from the source through the treatment process.

Different steps in the Water Treatment Process:

Coagulation 
Coagulation 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.



Sedimentation
The heavy particles (floc) settle to the bottom and the clear water moves to filtration.

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.