Michigan backflow testing rules
Michigan Administrative Code R 325.11404 (Supplying Water to the Public, Part 14) requires every type 1 public water supply to develop a comprehensive program to eliminate and prevent all cross connections, have the plan approved by the state, and carry it out.
Who sets the rules in Michigan
Michigan rule R 325.11402 requires every connection to a public water supply to comply with the backflow and cross connection sections of the Michigan plumbing code or Michigan residential code, plus local ordinances.
Michigan rule R 325.11404(4) requires each water supply to report annually to the state on the status of its cross connection control program.
Source: Community water supplies must run a cross connection control program
Is an annual test required?
Under Michigan rule R 325.11404(2)(d), each local program must set a schedule that tests every testable backflow preventer at least once every 3 years; local programs may require more often.
The City of Grand Rapids Water System states that the Michigan Plumbing Code requires testable backflow prevention devices to be tested annually by an ASSE certified tester.
Grand Rapids asks commercial, industrial and multi-family customers to submit a current year backflow test once every two years when notified; properties deemed high hazard submit every year.
Sources: State minimum: test at least once every 3 years; Grand Rapids: plumbing code calls for annual tests
Which properties need a backflow preventer
Michigan rule R 325.11403 prohibits unprotected cross connections with a public water supply for all customer types, including industrial, commercial, institutional, governmental, and single and multi-unit residential.
Michigan rule R 325.11404(2)(d) lets backflow preventers on lawn irrigation systems with no chemical treatment be tested once every 5 years, but only if the approved local program says so.
In Grand Rapids, one and two family homes with an irrigation system that has a testable backflow preventer submit a current year test once every five years when the Water System notifies them.
Lansing Board of Water and Light rules require an approved backflow prevention device on all lawn sprinkler or irrigation services, installed, owned, tested and maintained by the customer.
The Detroit Water and Sewerage Department is inspecting the inside and outside of all houses in Detroit for cross connections, free of charge, citing State of Michigan law and City ordinance.
Sources: Ban on unprotected cross connections covers every customer type; Grand Rapids: home irrigation backflow tests every five years; Lansing BWL: irrigation services need a backflow device; Detroit: DWSD inspects every house
Who may do the test
Michigan rule R 325.11405(2): since January 1, 2018, backflow test results are valid only if the tester holds an active ASSE 5110 certification.
How the test report is filed
In Grand Rapids, a backflow preventer that fails its test must be repaired by a licensed plumber and tested again before the test form is submitted by mail or email.
Lansing BWL rule 14.3: a defective backflow device must be repaired or replaced within thirty days, and test results go to the BWL Cross Connection Administrator.
Sources: Grand Rapids: failed devices are repaired and retested before the form is sent; Lansing BWL: repair defective devices within 30 days
If a test is missed
Michigan rule R 325.11405(3): if a cross connection is not removed or properly protected after a reasonable time, the water supply must shut off water to the premises or physically separate it from the public system.
Under Lansing BWL rule 14.4, failure to correct a potentially hazardous backflow condition found during an inspection may result in termination of water service.
Detroit's Buildings, Safety Engineering and Environmental Department runs cross connection inspections under the 2018 Michigan Plumbing Code Section 608; buildings that make no progress on violations receive a court notice.
Sources: Uncorrected cross connections lead to shutoff; Lansing BWL: failure to correct can end water service; Detroit: uncorrected buildings get a court notice
Finding a tester
The City of Ann Arbor's cross connection page links a List of Certified Backflow Testers and a backflow test report submission form.
Source: Ann Arbor certified tester list
Common questions
Is backflow testing required every year in Michigan?
Not every year under the state rule: Michigan rule R 325.11404 requires each testable backflow preventer to be tested at least once every 3 years, and local programs may require more often. Grand Rapids, for example, says the Michigan Plumbing Code calls for annual tests.