How City Water Systems Work

July 06, 2022

How City Water Systems Work

Municipal water systems are one of the most marvelous things in modern life. Having access to potable water at the turn of a handle has saved more lives than emergency medicine. But many people probably don't know exactly how all that relatively clean water makes it to their faucet. It is a complex process that is worth understanding.

How Do City Water Systems Work?

In most municipal water systems, the water is derived from a source such as a lake or river to be treated and pumped to faucets in homes, hospitals, businesses, and anywhere people need it. Wastewater is also often reused, and the treatment for water recycled in this way is a little more complex.

Treating the water is just one part of the process. A complete municipal water system works in the following 6 stages:

  • Source Water Acquisition: collection from rivers, lakes, and streams
  • Water Treatment: filtration prior to human use
  • Water Distribution: pumps and pipes that distribute water to homes and businesses
  • Wastewater Collection: pipes and pumps that carry water away from homes after it has been used
  • Wastewater Treatment: removal of water material and water purification
  • Stormwater Systems: ditches, pipes, and natural systems to collect rainwater

The Water Treatment Process

Regardless of its source, all water to be pumped into homes must be sufficiently clean to prevent sickness in the population and contamination in the system. This is achieved in a three to four step process.

Initial Treatment

The initial stage of treatment removes stones, gravel, sand, mud, and other larger particles from the water. This stage of treatment is usually done using a mechanical filtration system of some form. Sometimes this initial treatment can be done using a sand bed as a filter. Sand beds used for this purpose can be washed and reused many times.

Primary Treatment

In the second stage, the water is held in large tanks where remaining particulates are allowed to sink to the bottom and oily materials rise to the top. This makes removing these two types of contaminants easier to achieve. Once the oily and solid materials are removed, the water will be moved again to undergo the next treatment stage.

Secondary Treatment

At this stage, suspended biological materials and dissolved contaminants will still be present in the water. These contaminants can be addressed through exposure to UV light, ultra-fine filtration, or heating.

Tertiary Treatment

In the final stage, suspended and dissolved materials are exposed to a powerful oxidizing agent such as chlorine. The water is then filtered a final time before being disseminated into the municipal irrigation system.


This system has worked marvelously for many years all over the world to bring usable water to hundreds of millions of people. It has prevented untold illness and made our lives vastly easier and more productive. However, it is inevitable that after undergoing an industrial cleaning process and traveling through hundreds of miles of pipe, our water will have picked up contaminants that we really should not drink if we can help it.


That's where home water purification comes in. While municipal water systems are invaluable, it is up to us to ensure that the water that travels to our homes is truly and fully clean. Fortunately, we have high-quality water purification systems for any water purification needs.

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