Detroit Water and Sewerage Department: backflow testing rules
Serves Detroit, MI. Every point below comes from Detroit Water and Sewerage Department's own pages, linked; check your notice for your own deadline.
Who must test
- HydroCorp inspectors hand out free backflow preventers for verified common cross connections such as garden hoses; the owner installs them. Source.
- The BSEED plumbing survey and cross-connection control program covers industrial, commercial, assembly and other buildings, which receive a Certificate of Plumbing Re-Inspection. Source.
Notices and deadlines
- After receiving a notice, customers schedule a free inspection with DWSD's vendor HydroCorp by phone or online within 30 days. Source.
How the report is filed
- Backflow preventer test reports are emailed to the City's Buildings, Safety Engineering and Environmental Department (BSEED) Plumbing Division; the address is obfuscated on the fetched page. Source.
If a test is missed
- DWSD contacts the customer for a follow-up inspection within one year to verify outstanding cross connections were fixed. Source.
- Buildings in violation that make no progress correcting the cross connection receive a court notice. Source.
Program
- DWSD is inspecting the inside and outside of all houses in Detroit for cross connections; the free residential inspections are required by Michigan law and City ordinance. Source.
How to file your backflow test with Detroit Water and Sewerage Department
- Read your notice. After receiving a notice, customers schedule a free inspection with DWSD's vendor HydroCorp by phone or online within 30 days.Source.
- Book a tester Detroit Water and Sewerage Department accepts. See finding a tester below; book early so there is time to repair a failed assembly.
- The tester tests the assembly and fills in the test report. A failed assembly is repaired and tested again.
- The report is filed. Backflow preventer test reports are emailed to the City's Buildings, Safety Engineering and Environmental Department (BSEED) Plumbing Division; the address is obfuscated on the fetched page.Source.
- Keep a copy and set a reminder for next year. Set a free test-due reminder.
Finding a tester Detroit Water and Sewerage Department accepts
We found no tester list on Detroit Water and Sewerage Department's own pages. Use a state certified tester, and check your notice in case it names the testers or the portal it accepts.
Before you book, ask the tester:
- Are you registered with Detroit Water and Sewerage Department?
- Will you send the test report to the utility for me, and how?
- When is my report due? The date is on your notice; the tester needs time to test, repair if needed and file.
Read October 6, 2026. Program page: detroitmi.gov.