Protecting Our Water Supply: What You Need to Know About Backflow Prevention

To ensure clean, safe drinking water for everyone, the Missouri Department of Natural Resources (DNR) established the “Prevention of Backflow” regulation in 1987. This regulation outlines important responsibilities for owners of backflow prevention devices and addresses the risk of backflow contamination in systems such as lawn irrigation, car washes, medical facilities, and fire suppression systems. 

What Is Backflow?

The DNR defines backflow as “the unwanted reversal of flow in a water distribution or piping system due to changes in hydraulic pressure.” Two conditions must occur for backflow to happen:

1. Interruption of Normal Water Flow – A reversal in the usual direction of water flow.
2. Cross-Connection – A connection between the potable water system and a potential contaminant source.

Your Responsibility

If you own a backflow prevention device, it must be tested and inspected annually. This ensures your device is functioning properly to prevent contamination.

Have your tester forward the test report and fee to:
St. Louis County Department of Public Works
Attention: Cindy Basham
41 South Central
St. Louis, MO 63105-1719

For more details, you may contact:

• St. Louis County Department of Public Works
• Missouri Department of Natural Resources Public Drinking Water Program

Helpful Tips

Keep Your Meter Accessible

The round meter pit cover in your yard allows our team to access and maintain your water meter. Avoid covering it with landscaping materials, mulch, or other obstructions, as this may lead to estimated or inaccurate water bills.

Check for Leaks

Experiencing a high water bill? The most common cause is an undetected leak, with leaking toilets being the primary culprit. Visit the American Water Works Association website for helpful facts and tips about water usage and leak detection.

By following these guidelines, you play a crucial role in safeguarding our community’s water supply while maintaining an efficient and accurate water system.

Recommended Websites For More Information

American Water Works Association
6666 West Quincy Ave.
Denver, CO 80235
www.awwa.org

Missouri Department of Natural Resources
Public Drinking Water Program
P. O. Box 176, Jefferson City, MO 65102
www.dnr.mo.gov

U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20460
www.epa.gov

Metropolitan St. Louis Sewer District
2000 Hampton Ave.
St. Louis, Mo. 63139
www.stlmsd.com