Denver Water wants a test every year. We do the test, tag the assembly, and send the report in for you.
Denver backflow rules at a glance
| Water provider | Denver Water, Cross-Connection Control and Backflow Prevention Program |
|---|---|
| Who needs an assembly | All commercial, industrial, domestic, irrigation, and fire line services. Multi-family and single-family homes are assessed by site hazard, for example a well or pond on the property. |
| How often | At installation and every year after. Irrigation assemblies are tested as the water is turned on; Denver Water's irrigation testing season runs May through September. |
| Who can test | A tester with ABPA or ASSE certification. Fire line assemblies also need the state's Fire Suppression System Contractor – Backflow registration. |
| Reminder | Denver Water sends a notice 30 days before the annual test is due. |
| How reports are filed | Emailed to Denver Water's Cross-Connection Control office on its test report form. Mail is accepted too. |
| If you ignore it | Three notices within 60 days, then a $250 non-refundable penalty and service suspension status (in effect since May 1, 2025). |
| Program contact | Cross Connection Control, 303-628-5969 |
Summarized from Denver Water's published program information (source), checked October 2026. The notice from your water provider always has the final word on your due date.
Didn't get the notice?
Denver Water mails notices to the service address and to the backflow contact it has on file. If you manage the property for someone else, or the contact is an old tenant, notices go to the wrong place and the penalty shows up anyway. Denver Water's Customer Care line (303-893-2444) can update the backflow contact.
Got a survey letter instead?
Denver Water surveys commercial, irrigation, fire, and multi-family service lines. If a property doesn't pass, Denver Water gives the owner 60 days to install an approved assembly, using a licensed installer, and requires a test by a certified tester within 48 hours of installation. We can do that test, and walk you through what the survey is asking for.
What we do on a Denver backflow test
- Confirm the assembly type, size, and serial number against your provider's records
- Test every check valve and relief valve with a differential pressure gauge calibrated October 2026 and traceable to NIST
- Tag the assembly with the service date, our business information, and the tester's certification number
- File the completed report the way Denver Water requires
- Send you a copy of the report, with photos
If the assembly fails
Most failures come down to a dirty or worn check valve, a tired relief valve, or a split rubber part. Those get cleaned or rebuilt and retested, usually in the same visit, after you approve the price. If the body itself is cracked, usually from a missed winterization, the assembly has to be replaced. Replacing an assembly is installation work, which in Colorado needs a licensed plumber; we'll tell you exactly what's needed and do the retest once it's in.
Before we come out
- Have the notice from your water provider handy, or send a photo of it when you book
- Tell us where the assembly is, and leave any gate unlocked or the mechanical room open
- For sprinkler assemblies, the water needs to be on. If the system is still winterized, we can do the spring startup and the test in one visit.
Not sure what kind of assembly you have? PVB vs. DCVA vs. RPZ →
Backflow testing nearby
Aurora · Thornton · Westminster · Arvada · Northglenn · Broomfield · Golden · Lakewood · Englewood · Commerce City · Wheat Ridge · Parker · Boulder · Louisville · Lafayette · Greenwood Village · Centennial · Commercial & HOA testing · For plumbing & irrigation companies · Every provider's rules
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