Water Division

Columbia Missouri Water System

Notice water pooling up on your property or in the street?
Use our online Water Leak Form

Watch a video about the Columbia water system.

Download an update of our water bond issue projects in a pdf document. Currently we are working on increasing the water supply to Columbia's older schools for fire fighting purposes.

Water Quality

Information about changing the disinfection method to chloramines to lower the level of trihalomethanes in Columbia's water system.

Columbia's water is recognized for its high standards of quality. Our water is tested more frequently and more thoroughly than is required by law. The well water is monitored for any possibility of contamination and over 4,000 tests are run each year on samples at the Water Treatment Plant and from 40 locations throughout Columbia.

Columbia's drinking water meets or exceeds all quality standards set by the Federal Environmental Protection Agency and the Missouri Department of Natural Resources. For detailed information, please see our Water Quality report or the complete list of testing results.

Source of Water Supply

Columbia's water is pumped from wells that tap into a water-filled bed of sand and gravel beneath the bottom land bordering the Missouri River just southwest of the city. Melting glaciers washed sand, gravel and boulders downstream and left thick deposits along the course of the river. This geological formation is an alluvium and when saturated with water becomes an alluvial aquifer.

Water slowly moves through the aquifer, which acts as a natural filtration system. Forty-four billion gallons of water fill the area which is constantly replenished by groundwater sources. The wells average 110 feet deep, penetrating the aquifer near its bottom.

Water Treatment

Aeration: At the treatment plant, the water first flows through aerators and is exposed to air that is drawn through the aerators by fans. This oxidation of the well water reduces levels of iron, carbon dioxide and hydrogen sulfide that are naturally found in the water. Excess iron can stain laundry. Hydrogen sulfide causes an unpleasant odor in the water. Carbon dioxide consumes lime used in the softening process and increases the cost of water treatment.

Softening: Lime is then added to the aerated water, and a chemical reaction occurs between the lime and the calcium and magnesium dissolved in the well water. Heavy, insoluble particles of calcium and magnesium form and settle to the bottom of the softening basins, and as it accumulates, it is piped to lagoons where it is dried and later used as landfill. This process physically removes fifty percent of the hardness causing minerals from the water. Softened water enables you to use less laundry detergent and reduces scale formed in water heaters and pipes.

Filtration: Any particles remaining in the water after the softening process are filtered through layers of anthracite coal and sand. Chlorine may be added before or after filtration to prevent bacterial growth. Fluoride is added to meet Environmental Protection Agency recommendations and helps improve dental health.

Disinfection: Water must be disinfected to prevent bacterial growth and prevent disease causing illnesses like typhoid, hepatitis and cholera. Columbia uses chlorine to disinfect the water. The benefit of this method is that a small amount of chlorine remains in the water through the distribution system all the way to the faucet. Columbia will be adding ammonia in the disinfection process to slow the chemical reaction between the chlorine and the organic material. This converts the chlorine to chloramines which stops the formation of trihalomethanes. The Columbia City Council and the Missouri Department of Natural Resources have approved the switch to this disinfection method. Depending on the equipment delivery and installation schedule, the conversion should happen in August.

Water Distribution

Softened, filtered water is pumped from the water treatment plant to reservoirs at the West Ash, South Pump and Hillsdale pumping stations. The water is then pumped throughout the city to consumers. Water is stored in three water towers that provide capacity for peak flows and fire fighting.

Future Plans

In 2008 a Long Range Water Study was conducted by Jacobs Engineering Group, Inc. The objective of the study was to identify needed capital improvements to provide water service to Columbia customers for a 20-year period (2008 to 2028).

Click here to download the Long Range Water Study: file size is 4.89 MB.

Note: the figures from the report can be supplied by e-mailing a request to WLmail@gocolumbiamo.com