Backflow Laws: Michigan
Michigan Backflow Prevention Laws, Regulations, and Compliance Requirements
Michigan is one of three states nationally recognized as having the most comprehensive cross-connection control requirements (alongside California and Wisconsin). The Michigan Safe Drinking Water Act, Part 14 (R 325.11401-11407), administered by EGLE, requires water systems to implement comprehensive CCC programs including inspection of ALL customer types — commercial, industrial, and residential. Michigan requires an annual cross-connection control report to EGLE and ASSE 5110 certification for testers. This guide covers Part 14 in depth and programs for Detroit, Oakland County, Canton Township, Grand Rapids, and other major Michigan utilities.
Michigan State Regulatory Framework — Part 14
Michigan’s cross-connection control requirements are among the most comprehensive in the nation. They are established in Part 14 of the Michigan Safe Drinking Water Act Administrative Rules (R 325.11401 through R 325.11407), administered by the Michigan Department of Environment, Great Lakes, and Energy (EGLE). Michigan holds EPA primacy under the federal Safe Drinking Water Act.
Part 14 prohibits cross-connections and requires each water system to implement a comprehensive cross-connection control program. The program must include: inspections, testing, recordkeeping, and education. Critically, Michigan — unlike most states — explicitly requires water systems to develop programs for inspection, testing, and education of ALL customer types, including residential customers. Michigan reinforced the requirement for surveys of residential service connections in 2016, and EGLE requires water systems to develop a program for residential inspection and testing, not just commercial and industrial.
Michigan water systems must submit an annual cross-connection control report to EGLE documenting testing, inspection, and corrective action efforts. This annual reporting requirement — combined with the mandatory residential survey component — places Michigan in the highest tier of state cross-connection control regulation nationally.
Testing Frequencies Under Michigan Law
Commercial and industrial properties: annual testing is required by EGLE for all testable backflow assemblies. Michigan’s plumbing code works in conjunction with Part 14 to establish specific testing frequencies by assembly type. Testable assemblies must be tested upon installation, after repair or relocation, and at the frequency specified by the water system — which is typically annual.
Residential irrigation systems: EGLE requires backflow prevention devices on irrigation systems to be tested at least every 3 years. This triennial testing for residential irrigation is notably less frequent than the annual testing required for commercial assemblies, but it is a legally mandated minimum that makes Michigan one of the few states with an explicit residential irrigation testing requirement rather than leaving it entirely to utility discretion.
Michigan Tester Certification — ASSE 5110
Michigan EGLE references ASSE 5110 (Backflow Prevention Assembly Tester) as the standard certification for testers who perform required backflow assembly tests. ASSE International’s certified personnel database is the verification resource for tester credentials in Michigan. Many Michigan water authorities also accept ABPA certification as an equivalent credential. Testers must use calibrated differential pressure gauge equipment. Water systems are not required to accept test reports from non-certified testers.
High-Risk Residential Accounts Under EGLE's 2024-2025 Guidance
EGLE’s October 2025 guidance document clarifies that residential customers designated as having high-risk cross-connections must be assigned a routine reinspection frequency no different than a non-residential account. High-risk residential accounts include properties where cross-connections are known or suspected, or where chemicals are being used such as fertilizers for lawn irrigation. The identification and elimination of cross-connections at these accounts is of particular importance to EGLE. This expanded residential focus has been driving active residential inspection programs across Michigan — HydroCorp, Guardian Compliance Partners, and other specialized contractors have been engaged by many Michigan water systems to assist with residential program implementation.
Michigan Requires Residential Inspections — Not Just Commercial
The most significant difference between Michigan and most other U.S. states is that EGLE explicitly requires water systems to develop and implement cross-connection control programs for ALL customer types — including single-family residences. Most states focus exclusively on commercial and industrial accounts. Michigan has required residential surveys since 2016. If you own a single-family home in Michigan with an irrigation system, a well connection, or any other potential cross-connection, you may be contacted by your water system or their contracted inspector for a premises inspection. This is a state-mandated inspection under Michigan Public Act 399, Part 14A, and refusal can result in water service termination or fines.
Major Water Purveyors in Michigan
Great Lakes Water Authority / Detroit Water and Sewerage Department (GLWA/DWSD)
The Great Lakes Water Authority (GLWA) is the wholesale water supplier serving Southeast Michigan’s regional system, with the City of Detroit’s Water and Sewerage Department (DWSD) serving Detroit proper. The GLWA/DWSD system is the largest in Michigan, serving approximately 4 million people in the Detroit metro area including Oakland, Macomb, and Wayne counties and portions of Genesee and Washtenaw counties. The DWSD administers cross-connection control requirements for Detroit properties, while suburban communities served wholesale by GLWA each operate their own retail cross-connection control programs aligned with Part 14.
Oakland County Water Resources Commissioner
Oakland County’s Water Resources Commissioner operates one of the most long-established cross-connection control programs in Michigan. The Oakland County CCCP has been in effect since 1976, originally focused on commercial and industrial facilities and expanded to include residential customers in 2002 following changes in state rules. Oakland County inspects properties at minimum intervals of once every one to ten years depending on hazard classification. Commercial and industrial properties requiring testable assemblies must have them tested annually using the WRC test form. Oakland County staff perform inspections, which are included in water rates.
Canton Township
Canton Township has implemented a well-developed residential cross-connection program. Starting in 2020, residential customers with underground irrigation systems began being required to have their backflow devices tested and submit results at least once every five years. It is estimated over 11,000 Canton homes have underground irrigation systems subject to this testing requirement. Commercial and industrial facilities continue to require annual testing. Canton has contracted with HydroCorp to inspect and maintain the CCCP for residential accounts.
Pittsfield Charter Township
Pittsfield Charter Township has contracted with HydroCorp to inspect and maintain its cross-connection control program for both commercial, industrial, and residential accounts. Properties are notified by mail when required to be tested. Commercial and industrial facilities require annual testing. Residential customers with irrigation systems must have their backflow devices tested at the frequency required by EGLE and Pittsfield’s program.
Grand Rapids — Kent County
Grand Rapids City Water serves Kent County’s largest city and surrounding communities. Grand Rapids’ cross-connection control program aligned with EGLE Part 14 requirements includes commercial and industrial annual testing and residential inspection programs. Grand Rapids has been expanding its residential cross-connection survey activities consistent with EGLE’s 2016 mandate expansion.
Lansing Board of Water and Light
The Lansing Board of Water and Light serves Michigan’s capital city. Lansing’s cross-connection program covers commercial, industrial, and residential accounts consistent with Part 14. Annual testing for commercial assemblies is required. Residential accounts are inspected per the state-mandated schedule.
Michigan's Triennial Residential Irrigation Testing Is a Minimum — Not Annual
Michigan law establishes every three years as the minimum testing frequency for residential irrigation backflow devices. However, individual water systems may — and often do — require more frequent testing. Many Michigan utilities that have active residential programs require annual testing for all testable devices, including residential irrigation. Do not assume you can test your residential irrigation device every three years without confirming your specific water system’s requirements. Annual testing for all testable devices is often the standard even in residential applications.
Property Owner Compliance Summary for Michigan
Commercial/industrial: Annual testing by ASSE 5110-certified tester. Submit results to your local water authority.
Residential irrigation: Minimum every 3 years per EGLE Part 14. Your specific utility may require annual testing — confirm.
Residential inspection: EGLE mandates residential premises surveys. Cooperate when your water system or their contractor schedules an inspection.
Annual EGLE report: Your water utility files the annual report; your test records and compliance status feed it.
Records: Retain all test reports. Submit results using the WRC (Water Resources Commissioner) test form or your utility’s designated form within the required window.
Find a Certified Backflow Tester in Michigan
Find ASSE 5110-certified testers at getyourbackflowtested.com/backflow-testing-near-me/michigan-backflow-testing — covering Detroit, Grand Rapids, Lansing, Kalamazoo, Ann Arbor, Flint, and all major Michigan communities.
Michigan Regulatory Reference Links
| Resource / Agency | URL / Link Target |
|---|---|
EGLE — Cross Connection Control | |
Michigan Part 14 Cross Connection Rules Manual (2008) | |
EGLE — Residential Cross-Connection Guidance (October 2025) | |
Oakland County Water Resources — Cross Connection | |
Canton Township — Residential Cross Connection Program | |
ASSE International — ASSE 5110 Certified Tester Lookup |