What Actually Happens During the Water Treatment Process?

water treatment plant

We all know that our drinking water is “treated,” but most of us don’t know how. While drinking supplies in the U.S. are among the safest in the world, water can still become contaminated with water-borne germs such as Cryptosporidium, E. coli, Hepatitis A, Giardia intestinalis, and other pathogens. Every community is different—they have different regulations and processes to treat their water—but here’s what the average treatment system looks like.

Coagulation and Flocculation

Chemicals with a positive charge are added to the supply of water that’s being treated—these neutralize the negative charge of other things in the water like dirt and other dissolved particles. These particles then bind with the added chemicals to form larger particles, called floc.

Sedimentation and Filtration

The floc, or larger particles, eventually settle to the bottom of the water supply, leaving only the clear water on top. Once everything has settled, the clear water will pass through filters made up of various combinations of materials, such as sand, charcoal, gravel, etc., as well as through different pore sizes, in order to remove other dissolved particles. Even after the floc has separated, there can be smaller particles left over like dust, parasites, bacteria, viruses, and chemicals.


After the water has been filtered, a strong disinfectant like chlorine or chloramine may be added to kill any addition parasites, bacteria, or viruses. The chemicals added at this stage of the treatment process also supply an extra layer of protection to the water for when it’s eventually piped into homes and businesses. Germs and bacteria will have a harder time entering the water once it’s in your home because of this important step.

While the treatment process certainly varies from community to community, this is what you can expect from a basic system. It will also depend on where the water is coming from! Groundwater typically needs less treatment than surface water sources like rivers or lakes.
If you want guaranteed fresh, pure water, contact Water Way today to find out about their water delivery and installation!