Public Water Supply District 1 of Jefferson County: backflow testing rules
Serves Jefferson County, MO. Every point below comes from Public Water Supply District 1 of Jefferson County's own pages, linked; check your notice for your own deadline.
Who must test
- Required on lawn irrigation systems; some residential and commercial uses by type of business. Source.
Notices and deadlines
- Customers are assigned a cycle; contact the office to learn which. Source.
- Customers are assigned a cycle; contact the office to learn which. Source.
How the report is filed
- Email backflow@pwsd1jeffco.org with the DNR test report. Source.
Approved testers
- District publishes a Backflow Tester List PDF. Source.
Program
- Jefferson County, MO district. Source.
Read October 6, 2026. Program page: pwsd1jeffco.com.