From the Treatment Plant to the Tap: Water Purification’s 5 Phases

The water you use to shower or to wash your clothes follows a long journey from the treatment plant to the tap. Water purification is far more complex than installing a water filter at home. When you want to understand how your water becomes clean and safe to drink, you have to take a look at the process that happens beyond your home’s own pipe work.

waterHere are the five stages of water purification, as explained by the experts at Clean and Clear:


The screening stage happens when the water from rivers and lakes enters the treatment plant. This is the part where a basic screen separates the large sediments from the water – from plants to fish. Screening is not necessary in the case of groundwater, as the layers of earth already serve as a filter.


After screening, the personnel at the treatment plant mix certain chemicals like alum into the water. This is the coagulation process. The chemicals react and form sticky particles called floc. Now, this substance serves as a magnet that attracts dirt particles. Eventually, the floc becomes heavy and dense enough to sink.


Post-coagulation, the water flows into a basin where it undergoes sedimentation. The water would simply sit there, whilst the heavy floc sink at the bottom of the tank.


The filtration process comes next, in which the water has to go through multiple layers of sand, gravel, and occasionally, charcoal. This step removes smaller particles that the first three stages may have missed.


The last stage is disinfection, where chemicals like chlorine are added to kill any remaining bacteria or microorganisms. For groundwater, disinfection may only be the process necessary. This, however, is only applicable when groundwater is the ONLY source of water in a treatment plant.

After disinfection, the water stays in a reservoir until it goes through distribution. From there on, the water makes its way to homes, establishments, and all other places that need some H2O.