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The Process


In Meridian, drinking water comes from any of the 25 wells located around the City that draw from groundwater in three underground aquifers. An aquifer is a natural, underground layer of rock or sand that yields water. Groundwater is found in the spaces between the rock and sand.

When new City wells are constructed, the City takes great efforts to explore water quality at different depths beneath the ground surface in order to find safe drinking water free from harmful contaminates. This is done by first constructing “test wells".

After finding the best quality water, the City constructs wells with full-depth well seals (from the selected depth to ground surface) so water is extracted only from those selected areas. These full-depth seals are made using a special grout that is pumped into place. The seals make sure that the natural barriers, like clay, stay intact and continue to prevent the vertical movement of waters with differing qualities. The City takes the responsibility of delivering safe water very seriously. The total investment to bring a City well on line is over $1.6M.

Learn more about the efforts that the City takes to protect our water sources.


The large majority of Meridian's water storage is in our natural aquifers. However, above ground storage facilities provide redundancy, ensuring that Meridian residents are never without water.

In total, the City has 4 million gallons of combined storage capacity for drinking water. Two additional storage facilities are slated to be built within the next ten years, which will increase the capacity to close to 9M gallons.

While ample supplies of water are important to service our 40,000 accounts during peak usage hours, it is also important to have plenty of water on hand in case of emergency. The Meridian Fire Department relies on water storage to aid them in fighting fires.


Once the groundwater is drawn up through the wells, it is disinfected and, in some cases filtered first. Water that requires filtration is pumped out of the ground and into a pressurized filter vessel (see photo at right). This water is then sent through a special filter media that removes the iron and manganese molecules that contribute to brown water. This filtered water is then disinfected and sent into the water distribution system and to your home.

The City continues to explore alternative treatment techniques to increase our options and provide the optimal treatment process for each of our unique water sources. Of course, these studies and construction of such complicated treatment facilities take time and resources. We plan to complete our water treatment remediation projects for existing wells by 2028. This includes the completion of 6 additional treatment sites.

With the completion of our five existing treatment facilities, we are already seeing significant improvements in iron and manganese removal and the reduction of brown water occurrences City-wide. We appreciate your patience as we strive to improve the quality of water delivered to your home.


In an effort to improve water quality and reduce discolored water occurrences, the City conducts annual flushing events. We notify residents for both routine and non-routine flushing through mail inserts, social media updates, Nextdoor notifications, and email.

Learn more about the City's annual flushing program.


Meridian distributes water to over 40,000 customers. Beneath your feet run nearly 640 miles of pipe that carries our clean drinking water. Those pipes distributed 3.8 billion gallons of water in 2020.

For more information on distribution and where the water goes, visit our By the Numbers page!

Cross Connection

A cross connection is a link between a consumer's drinkable (potable) water and potentially contaminated water lines, such as irrigation lines, private wells or tree and flower planters. If there is a change in pressure, water can flow backward into your home's plumbing and into the City's system. This is known as backflow and it can pose serious health risks.

City and State of Idaho ordinance 9-3 requires annual testing of all of the thousands of existing backflow prevention assemblies located throughout our City. Backflow prevention assemblies range from small vacuum breakers on household irrigation systems to larger double check and reduced-pressure principal assemblies for commercial applications. Click here for a list of local professionals who can perform the proper testing for you. These tests must be submitted to the City.

Dual connections are not allowed and must be removed, per City Resolution 10-763. Dual connections are physical connections between drinking water lines and pressurized irrigation water lines. Connections between these two different sources can be dangerous as irrigation water is not meant for direct consumption.

Backflow prevention devices are critical in protecting the integrity of our community's water supply and must be tested annually. Please help us by doing your part and testing your assembly. If you are not sure if you have the proper backflow protection on your plumbing system or if you have a possible Dual Connection in need of removal, please contact us!

Usage Tips

The next step in the process is where you come in. After the water is delivered to residents, our customers use it for a wide variety of tasks. There are a lot of things that you can do to help keep the process flowing smoothly. Visit our Water Wise page to learn more about conservation and infrastructure protection.

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