Water Utility

About Water

We rely on the City’s water system to treat and transport water to 51,000 customers (a population of over 126,000 people) residing and working in our 89 square mile service area. In order to proactively respond to customer demands through 2033, Columbia Water & Light contracted with Jacobs Engineering Group to analyze how to best provide water service. See the full Long Range Water System Studyopens PDF file for details on recommended Improvement Projects.

Utility outage map

Use  the outage viewer to locate utility outages and boil advisories.

View outage map

Boil orders & advisories

For more information on boil orders, please see your Boil Advisories and Boil Orders page.

Water quality

Columbia’s water is tested more frequently and more thoroughly than is required by law. The well water is monitored for any possibility of contamination and multiple tests are run daily throughout the treatment process. The Utility tests samples from more than 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 the City of Columbia 2022 Water Quality Reportopens PDF file  and the Source Water Protection Planopens PDF file . You can also view the City of Columbia 2022 Water Quality Report on the Department of Natural Resources opens PDF file website.

Recent MDNR testing results and reportable events:

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. Long ago, 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.

The Integrated Water Resource Plan (IWRP) Final Reportopens PDF file  was completed in March 2017 and will guide the best combination of strategies for ensuring a sustainable and cost-efficient water supply. 

U.S. geological survey resources

In 1992, an agreement among the USGS, the City of Columbia and the Missouri Department of Conservation began groundwater monitoring in the McBaine Bottoms around the City’s wetland treatment units and on the Eagle Bluffs Conservation property.

The objective of these studies is to monitor the water quality throughout the McBaine Bottoms, to track changes in groundwater quality in the vicinity of the public supply well field and the Eagle Bluffs Conservation Area, and to provide the City with the information needed to protect the well field and ensure good quality drinking water.

Interactive USGS map to access water data from Columbia wells

Water resources investigation reports

2003: Ground-Water Flow and Ground- and Surface-Water Interaction at McBaine Bottoms, Columbia, Missouri—2000–02

2006: Water-Quality Data, 1999-2005, and Ground-Water Level Data, 2004-2005, for McBaine Bottoms, Including the Eagle Bluffs Conservation Area, Columbia, Missouri

2008: Ground-Water Flow, 2004-07, and Water Quality, 1992-2007, in McBaine Bottoms, Columbia, Missouri

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.
  • 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 storage lagoons. This process physically removes 50 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. The disinfection method used in Columbia allows for disinfection of the water through the distribution system all the way to the faucet. The Columbia Water Treatment Plant first disinfects the water with chlorine, than adds ammonia, forming chloramine. Chloramine is a common disinfectant that has been used for the last 90 years. There are 0.6 milligrams of ammonia added per liter of water. For comparison, this would be similar to adding six grains of table salt to a one gallon container of water. More information on disinfection methods can be found in this 2009 reportopens PDF file from the University of Missouri’s Department of Civil and Environmental Engineering and the Missouri Water Resource Research Center.
    For more details on Columbia’s Water treatment processopens PDF file with pictures, follow the link.

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 water use and fire fighting.

The following subdivisions are urged to stick to an Irrigation Scheduleopens PDF file  this summer: Bradbury Estates, Creek’s Edge, Thornbrook, Steeplechase, and Wyndham Ridge

Engineering

McBaine Water Treatment Plant Improvement Project

Columbia Water & Light’s McBaine Water Treatment Plant (WTP) Improvement Project will restore the plant’s capacity to treat 32 million gallons of water per day and include rehabilitation and replacement projects that will enhance the performance and extend the life of this critical facility.

The sale of the bond from the voter-approved 2018 Water Ballot Initiative that will fund the project closed Oct. 26, 2023.

With the sale of the bond, an adjusted customer base charge will go into effect beginning with the first billing cycle in November 2023. For more information, visit our FAQ page:

Construction service manual

Rules, Regulations and Policy relating to Installation and Extension of Water and Electric Facilities

Facilities connection requirements

This document outlines the requirements for generation, transmission, and end-use facilities of customers to be connected to the Columbia Water & Light Department (CWLD) electric system.  Its purpose is to promote safety of people and equipment, compatibility between customer facilities and CWLD facilities, and maintenance of reliability of the regional electric system when a customer requests an interconnection with CWLD.  It complies with the requirements of the NERC Standard FAC-001 and FAC-002.

Water main construction specification

This document is provided for developers constructing water mains within the City of Columbia’s water territory. The official, signed copy is on file with the Columbia Water & Light Engineering Division and might include updates that have not been posted on the web site yet. The web document is only meant as a reference.