1. Coagulation / Flocculation
Coagulation and flocculation remove color, turbidity, algae, and other microorganisms from surface waters. Liquid aluminum sulfate (alum) and polymer are added to the untreated water during coagulation. When mixed with the water, this causes the tiny particles of dirt in the water to stick together or coagulate. Next, groups of dirt particles stick together to form larger, heavier particles called flocs which are easier to remove by settling or filtration.
2. Sedimentation
The flocculated water then flows to the following primary unit of the water purification process, called sedimentation. The sedimentation process aims to remove suspended solids (particles) that are denser (heavier) than water and reduce the particulate load on the filters.
As the water and the floc particles progress through the treatment process, they move into sedimentation basins where the water moves slowly, causing the heavy floc particles to settle to the bottom. Floc which collects on the bottom of the basin is called sludge and is piped to drying lagoons.
This sedimentation process removes almost ninety percent of the solids in the water. The more transparent water on the surface is collected in the launder tubes that direct the water to the filter gallery to remove the remaining ten percent of solids.
3. Water filtration process
Water flows through filters of varying compositions (sand, gravel, and charcoal) and pore sizes to remove dissolved particles, such as dust, parasites, bacteria, viruses, and chemicals in the water filtration process. Filtration collects the suspended impurities in water and enhances the effectiveness of disinfection.
4. Disinfection
After the water has been filtered, a disinfectant (for example, chlorine, chloramine) may be added to kill any remaining parasites, bacteria, and viruses and protect the water from germs when piped to homes businesses. Chlorine is used because it is a very effective disinfectant, and residual concentrations can be maintained to guard against possible biological contamination in the water distribution system.
5. Sludge Drying
Sludge drying is transforming sludge into valuable products or green fuel. It significantly reduces the volume and weight of the sludge so that it is easier to recover.
6. Fluoridation
Water fluoridation is the controlled addition of fluoride to a public water supply to reduce tooth decay. Fluoridated water contains fluoride at a level that is effective for preventing cavities.
7. Water Process Laboratory
The water treatment plant has a process laboratory to ensure that the water cleaning process is optimized and that the water is safe to drink.