If a letter showed up from your city titled "Cross Connection Control Program Testing Notice," you are not in trouble and you did nothing wrong. It is a routine annual requirement, it has a deadline, and getting it handled is straightforward once you know what it is asking for. Here is what the notice means, what gets tested, and exactly what to do next.
What a cross connection notice actually is
A cross connection is any point where your plumbing could let non-potable water flow backward into the clean drinking water supply. Backflow is when that reversal actually happens, usually during a pressure drop, a water main break, or heavy demand on a hydrant. A backflow prevention assembly is the device that stops it.
Your city runs a Cross Connection Control Program to make sure those assemblies are present and working. Once a year, the program sends a testing notice to properties that have a testable assembly, asking you to have it tested by a licensed plumber and the results submitted before a due date. That letter you are holding is that request.
Why your city sends these (and who is behind the letter)
Cross connection control is required under the Michigan State Plumbing Code and the rules of the Michigan Department of Environment, Great Lakes & Energy (EGLE). Each city or water authority administers its own program locally, which is why the letter comes from your municipality.
Many Metro Detroit communities outsource the program administration to a company called HydroCorp, so the notice, the reference number, and the online results portal at gethydrosoft.com all run through them. If your letter mentions HydroCorp or Hydrosoft, that is normal. The water department still owns the requirement; HydroCorp just tracks it.
Who gets these notices
Both homeowners and commercial properties get them. You are almost certainly on a testing cycle if you have any of the following:
- A lawn irrigation or sprinkler system (a very common trigger, usually protected by a pressure vacuum breaker)
- Fire suppression and sprinkler lines
- Boilers or closed-loop heating systems
- A medical, dental, or laboratory facility
- A commercial kitchen, car wash, or any process-water connection
If your property has one of these and a backflow assembly is installed, expect an annual notice whether or not one has arrived yet.
What gets tested
A certified tester uses calibrated gauges to confirm the assembly holds and relieves pressure exactly the way it is designed to, so the check valves seat and the relief opens at the right point. The result is recorded on a report and submitted to the program, in most local cities online through gethydrosoft.com using the reference number on your letter.
The assembly types you will see on these notices are:
- Reduced pressure zone (RPZ) assemblies, used on higher-hazard connections like medical and process water
- Double check valve (DC) assemblies, used on lower-hazard connections
- Pressure vacuum breakers (PVB), the type most lawn irrigation systems use (a FEBCO 765 is a common model on these letters)
Which one you have depends on the hazard level of the connection, and the notice usually lists the device, manufacturer, and model.
What to do after you get the notice
The letters spell out three steps, and they are the same across most Metro Detroit cities:
- Step 1: Hire a licensed plumber to test the assembly. It has to be a certified backflow tester, not a handyman, and not the homeowner.
- Step 2: Schedule it before the due date printed on your notice (often 30 to 60 days out).
- Step 3: The tester submits the results to the program online. Paper, fax, and email submissions are no longer accepted in most local programs; the passing result has to be entered through the portal.
If the assembly fails the test, it has to be repaired or replaced and then retested before the result will pass.
What happens if you miss the deadline
A missed test is not a quiet problem. Depending on your city, it can lead to compliance notices, fines, and in some cases the water authority can move to shut off service until the assembly is tested. For a business that cannot run without water, a routine annual task becomes a real disruption. The good news is it is entirely avoidable by scheduling before the date on the letter.
Frequently asked questions
How often do I need backflow testing? Annually, in almost every Metro Detroit cross connection control program.
Can I test it myself? No. The result has to come from a certified tester with calibrated gauges, and it must be submitted through the program portal.
How much does it cost? It varies by assembly type and site. We will give you a clear price up front before any work.
My sprinkler system got a letter. Is that normal? Yes. Lawn irrigation systems are one of the most common triggers because of the pressure vacuum breaker on the line.
What if my assembly fails? It gets repaired or replaced and retested. We can handle the test, the repair, and the resubmission so you are not coordinating multiple trips.
Who do I send the results to? Your tester submits them, usually online to your city's program (gethydrosoft.com for HydroCorp-administered cities), using the reference number on your notice.
How Bulldog Mechanical helps
Bulldog Mechanical handles cross connection and backflow work for commercial, industrial, healthcare, and residential properties across Metro Detroit, including Sterling Heights, Warren, Clinton Township, Macomb Township, Troy, the Grosse Pointe area, and the surrounding communities. We test the assembly, document it, submit the result to your city's program, and if anything fails we repair or replace it and get you back in compliance. For facility managers with multiple buildings, we keep every assembly on schedule so a deadline never sneaks up on you.
If you have a notice in hand, grab the reference number and the due date off the letter and reach out. Call (586) 280-4101 or send a few details through the quote form, and we will get you scheduled and compliant before the deadline.