The City of O'Fallon Water and Sewer Department provides water and sewer service to parts of O'Fallon City limits. Use Address Look-Up to determine services for a selected address.
- Information on O'Fallon's Sewer Lateral Insurance Program
- MO DNR Water Protection Program Fact Sheet: Boil Orders and Boil Water Advisories
Water and Sewer emergency? Please contact 636-379-5488.
O’Fallon’s water system consists of a 6.0 million gallon per day, state-of-the-art RO/Membrane Water Treatment Plant with five alluvial wells. This water supply and treatment is complimented with six additional deep wells, four booster pump stations, high service pumps, five elevated storage tanks, two ground storage tanks and over 161 miles of cast iron, ductile iron, and PVC distribution lines.
The system serves nearly 13,000 customers.
- Water and Sewer Delinquent Notice (PDF)
- 2014 Consumer Confidence Report for Drinking Water
- Correct/incorrect irrigation system connections (PDF)
- Tips to improve your water pressure (PDF)
The City's Water and Sewer Department operates and maintains the water supply, including the water treatment plant, wells, booster stations, transmission lines, distribution systems, along with 24/7 emergency response and repair, meter reading, billing, water sampling and testing, line locations as well as performing predictive and preventive maintenance. The City has duly licensed, State-certified operators who are responsible for system operations and maintenance.
For service calls and billing questions, contact:
Also operated by the Water and Sewer Department, the sewer system includes a vast collection system and full scale, state-of-the-art regional wastewater treatment plant with a capacity of 11.25 million gallons per day, complete with three full equalization basins, a Class A bio-solids dewatering and handling facility, large capacity interceptor sewers ranging up to 48 inches in diameter and large capacity wastewater pumping stations located at strategic points in the system. The collection system consists of over 195 miles of interceptor and collector lines ranging in size from 6 inches to 48 inches.
Originally constructed in 1984, the wastewater treatment plant, utilizes an activated bio-filter process with four unit primary and four unit secondary clarifiers, three high-capacity variable speed submersible bio-tower lift pumps, three bio-filter towers, four aeration basins, and an effluent pumping station, sludge digester and an ultraviolet effluent disinfection process.
The sewer system serves nearly 16,000 customers. The City of O’Fallon provides for the full service operations and maintenance of the wastewater collection, pumping and treatment systems, including customer service and billing, with duly State licensed operating personnel.
Contact Water and Sewer
Water and Sewer 24-Hour Emergency Phone Number - 636-379-5488
Customer Service and Billing - 636-281-2858