Commercial Backflow Testing in Troy, MI: A Compliance Guide for Local Business Owners

If you own or manage a commercial property in Troy, the City requires you to test your backflow prevention devices once a year. The test must be done by a licensed plumber with ASSE backflow tester certification, and the plumber, not you, submits the report through the City’s Swift Comply system. Here’s the step-by-step process, what to ask a tester before you hire one, and who to call at the City if you have questions. For Troy’s residential rules and the general overview, see our Troy backflow testing guide.

What Troy Requires of Commercial Properties

These requirements come straight from the City of Troy’s backflow testing page.

Requirement What the City of Troy Says
Who must test Every commercial and residential property must install and routinely test its backflow prevention device or devices
How often (commercial) Once a year
Who can test A licensed plumber with ASSE backflow tester certification, or an ASSE-certified plumbing apprentice working under the direct supervision of a licensed plumber
Who files the report The tester, through the City’s Swift Comply program
Who to ask about commercial testing The City’s Cross Connection Inspector, Justin Kilburn, at 248.524.3398

 Why the City Requires It

Red industrial fire sprinkler piping with a large manual shut-off wheel, a central valve, and two pressure gauges against a white brick wall.

Backflow is when water flows the wrong way and pulls contaminants back into the drinking water supply. A backflow preventer is the mechanical device that stops that. The City points out that these devices can fail from wear and tear, corrosion, freezing, water conditions, and misuse, which is why a passing test every year matters. A device that looks fine from the outside can still be failing inside.

The rules sit inside a state framework. Under Part 14 of Michigan’s Safe Drinking Water Act rules, each public water supply must run a cross connection program with inspections, testing, recordkeeping, and education. According to Michigan’s EGLE, a customer with a testable device can expect a letter asking for a test by a professional tester with ASSE 5110 certification, and the cost of installation and testing is often paid by the water customer.

Your Compliance Checklist

  1. Find your assemblies. Many commercial properties have separate domestic, fire protection, and irrigation water lines, and each line may have its own backflow assembly. The City’s testing reminder lists the known backflow assemblies at your address, so start there, then have your plumber confirm what’s actually installed.
  2. Hire a qualified tester. Troy requires a licensed plumber with ASSE backflow tester certification. This is not a job for in-house maintenance staff unless they hold those credentials.
  3. Confirm the tester is registered with Swift Comply. The City requires testers to register before they can submit reports, and registration requires a plumbing license, an ASSE certification card, and calibration sheets for the gauges they use. Ask your tester to confirm they’re registered.
  4. Schedule the test and give access. Make sure the tester can reach every assembly on the property, including any in mechanical rooms or fire sprinkler rooms.
  5. Let the tester file the report. The City says the tester submits every report through Swift Comply. You don’t file it yourself.
  6. Keep your own copy. Ask for a copy of the completed report for your records. The City also posts a blank test sheet if you want to see what a full report looks like.
  7. Calendar next year’s test. Commercial testing is annual, so set a recurring reminder.

Questions about your specific property?  the City’s Cross Connection Inspector handles commercial backflow questions at 248.524.3398. When in doubt, the City is the authority on what Troy requires.

Which Commercial Properties Usually Have Backflow Assemblies

Any commercial property with a connection to the public water supply that needs protection against backflow can have one. Bison Plumbing’s backflow testing service regularly tests devices at schools, hospitals, dental manufacturing facilities, car washes, auto body shops, gas stations, doctor and city offices, electro-plating shops, and chemical and manufacturing plants. Most commercial and industrial properties also have separate taps for domestic water, fire protection, and landscape irrigation, which is why one property often has more than one assembly.

What to Ask a Backflow Tester Before You Hire

  • “Are you a licensed plumber with ASSE backflow tester certification?” This is the City’s baseline requirement.
  • “Are you registered with Troy’s Swift Comply system?” Without registration, they can’t submit your report.
  • “How many assemblies will you test, and what does each one cost?” Pricing depends on the number and type of assemblies, so ask for a per-assembly written quote.
  • “What happens if an assembly fails?” The City’s page doesn’t spell out the repair and retest steps, so ask your tester how they handle it before the report is filed.
  • “Can you handle repairs if something fails?” Bison’s technicians repair and inspect assemblies for code compliance when a test fails, which saves a second contractor visit.

If You Manage More Than One Property

An open three-ring binder with a blank planner page sits on a wooden desk next to a cup of coffee and glasses.

Each address has its own assemblies and its own list in the City’s system, so a portfolio means a separate annual test for every property. A simple tracker with each address, the assemblies on site, and the test date makes the annual cycle much easier to manage. For a broader view of what Bison handles for businesses, see its commercial plumbing services page, and for Troy-specific details visit the Troy service page.

Frequently Asked Questions

How often does a commercial property in Troy need backflow testing?

Once a year, according to the City of Troy.

Who submits the test report to the City?

The tester does, through the City’s Swift Comply program. The City requires testers to register with Swift Comply before they can submit any reports.

Can my maintenance staff test our backflow assembly?

Only if the person is a licensed plumber with ASSE backflow tester certification, or an ASSE-certified plumbing apprentice working under the direct supervision of a licensed plumber. Otherwise, the test has to be done by a qualified outside plumber.

What if I don’t know how many backflow assemblies my property has?

Start with the list on the City’s testing reminder, which shows the known assemblies at your address, and ask your plumber to confirm what’s installed. If something doesn’t match, call the City’s Cross Connection Inspector at 248.524.3398.

Who do I call at the City with questions?

For commercial backflow testing, call the Cross Connection Inspector at 248.524.3398.

Troy’s commercial backflow rule is simple on paper: test once a year, use a certified plumber, and let that plumber file through Swift Comply. The work is in the details, like knowing every assembly on your property and confirming your tester is registered, and getting those right is what keeps an annual test from becoming an annual headache.

Bison Plumbing: Commercial Backflow Testing for Troy Businesses

Bison Plumbing is a family-owned, Michigan-licensed plumbing contractor serving Macomb and Oakland County since 1998, and it tests and certifies backflow prevention devices for commercial and residential properties.

Contact us today to schedule your required test before your annual deadline.

Due for your annual backflow test in Troy?

Bison Plumbing’s licensed, certified technicians test commercial assemblies across Macomb and Oakland County. Ask for a per-assembly written quote.

Schedule Commercial Backflow Testing | (248) 247-7707

Written & reviewed by Jeff Bianchini Co-founder, Bison Plumbing, Inc. · Michigan (LARA) licensed plumbing contractor · Serving Warren & Metro Detroit since 1998 Jeff co-founded Bison Plumbing in Warren, MI in 1998 and has spent his career on Metro Detroit sewer and drain lines — camera-first diagnosis, CIPP lining, and trenchless pipe bursting. He reviews every sewer and drain guide on this site for technical accuracy against current Michigan plumbing code and field practice in Macomb and Oakland County. Reviewed for technical accuracy by a Michigan LARA licensed plumbing contractor | Last updated: September 1, 2026
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