Public Water Supply District No. 2 of St. Charles County: backflow testing rules
Serves St. Charles County, MO. Every point below comes from Public Water Supply District No. 2 of St. Charles County's own pages, linked; check your notice for your own deadline.
Who must test
- All lawn irrigation systems, fire sprinkler systems and commercial service lines must have a backflow device tested annually by a State of Missouri certified tester. Source.
- Double check assemblies and reduced pressure devices must be tested at installation and at least every 12 months; double checks are overhauled at least every 30 months and RPs at least every 5 years. Source.
Notices and deadlines
- Annual backflow test reports are due at the Water District office by June 30 every year. Source.
Tester registration
- A Certified Backflow Prevention Tester is a person who completed training and is recognized by the State of Missouri as competent to test, check and rebuild backflow devices. Source.
Fees
- Reports received after June 30 are charged a $30 late fee; reports not received by July 30 get an additional $30 fee. Source.
If a test is missed
- Reports not received by July 30 are scheduled for disconnection, and service is not restored until the problem is corrected. Source.
- Defective backflow devices must be repaired or replaced at the user's expense within 30 days of discovering the defect. Source.
Program
- The District's Rules and Regulations (2022 PDF) set its backflow program in Rule #10, Backflow Prevention. Source.
Read October 6, 2026. Program page: waterdistrict2.com.