Centennial's backflow rules depend on your water district. Here's how ECCV, ACWWA, Willows Water, and Southgate each handle it.
Centennial backflow rules at a glance
| Which district? | ECCV serves eastern Centennial, roughly east of Parker Road and north of Arapahoe Road. ACWWA serves areas such as Dove Valley and around Centennial Airport. Willows Water covers Caley Drive to County Line Road, between University Boulevard and Quebec Street. Southgate serves parts of west Centennial. Your water bill names yours. |
|---|---|
| ECCV | Every premises with a backflow device has it inspected and tested at least once a year by a state-certified tester, at the owner's expense. Results go to the district within 10 days of the test (Rules 9.2, Water Specifications 2.17). |
| ECCV irrigation | Irrigation-only connections need an assembly. ECCV's June 2026 water specifications don't approve double checks or PVBs for landscape irrigation. |
| ACWWA | Commercial and industrial sites, fire mains, irrigation services, and properties with more than two units on one meter are tested every year, due one year after the last test. Most single-unit homes are exempt unless there's a hazard such as a dedicated irrigation tap or a well. |
| ACWWA testers and reports | Any ASSE- or ABPA-certified tester. Results are emailed to the Backflow Program Coordinator at Backflow@ACWWA.com. As of 2026, ACWWA no longer tests non-compliant devices itself. |
| ACWWA late tests | A Notice of Violation gives 60 days. After that come penalties ($250 first violation, $500 repeat, $1,000 chronic) and shut-off, with a $100 shut-off fee. |
| Willows Water | Commercial, industrial, irrigation, and fire services, multi-family buildings with 3 or more units, and properties with a well or pond need an assembly; single-family homes are assessed case by case. Tested at installation and every year. The district offers testing, or you can use a certified third-party tester. |
| Willows reports | Passing reports emailed to backflows@willowswater.org within 10 business days of the test (late reports are rejected); failures within 24 hours |
| Southgate | Denver Water runs the program for Southgate customers: Southgate backflow rules |
Summarized from each district's published rules (ECCV, ACWWA, Willows Water, Southgate), checked October 2026. The notice from your water provider always has the final word on your due date.
Find your district first
Centennial is one city with several water providers, and each one decides who has to test, which assemblies it accepts, and where the report goes. The name on your water bill tells you which rules apply. Send us a photo of your notice when you book and we'll file the report the way that district wants it. If you're a Southgate customer, see backflow testing for Southgate Water customers.
ECCV irrigation assemblies
ECCV's current water specifications require an assembly on irrigation-only connections and don't approve double checks or pressure vacuum breakers for landscape irrigation. If your notice says your assembly type isn't accepted, replacing it is installation work for a licensed plumber; we test the new one once it's in.
What we do on a Centennial 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 ECCV, ACWWA, Willows Water, or Southgate 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
Denver · Aurora · Thornton · Westminster · Arvada · Northglenn · Broomfield · Golden · Lakewood · Englewood · Commerce City · Wheat Ridge · Parker · Boulder · Louisville · Lafayette · Greenwood Village · Commercial & HOA testing · For plumbing & irrigation companies · Every provider's rules
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