In Colorado, the state sets the framework, but your water provider sets the details: who has to test, when the report is due, and where it goes. Here's how it works across the Denver metro.
The statewide rules
- Every water provider runs a cross-connection control program. Colorado's drinking water regulations require it, and the state's backflow rule (Regulation 11.39) was updated effective October 15, 2023.
- Testers must be certified. Colorado's 2025 backflow law (HB25-1077) defines a certified cross-connection control technician as someone holding a backflow prevention assembly tester certification from ASSE or ABPA.
- Testing and repair don't require a plumbing license, but installation does. The same law exempts people who inspect, test, or repair backflow devices from plumbing licensure; installing or removing a device still requires a licensed plumber.
- Tested devices get tagged. Since July 1, 2025, a certified technician who tests or repairs a device has to attach a tag showing who did the work and when, along with their certification number.
- Fire sprinkler assemblies are separate. Testing backflow devices on fire sprinkler systems requires a state fire suppression contractor registration for backflow.
Provider by provider
| City / provider | Who has to test | How the report is filed | Late or failed tests |
|---|---|---|---|
| Denver Denver Water | Commercial, industrial, irrigation, and fire services; homes when the site has a hazard such as a well or pool | Emailed to Denver Water on its test report form | $250 penalty after three unanswered notices |
| Aurora Aurora Water | Assemblies in Aurora Water's program, before occupancy and then at least yearly | Aurora Water's online portal, by a registered tester | $1,000 at 30 days late, $2,000 at 60 days |
| Thornton City of Thornton | Commercial, industrial, and multi-family properties with more than two units | BSI Online, which charges a fee per report | Failed tests reported within 24 hours; water service can be disconnected |
| Westminster City of Westminster | Commercial, industrial, irrigation, and fire services; homes by site hazard | BSI Online | See the city's notice |
| Arvada City of Arvada | Every assembly in the program, every year | Arvada's SAMS portal, using the letter code on your notice | Late tests need an authorization code from the city |
| Northglenn City of Northglenn | Commercial, industrial, and multi-family, including townhomes; RPZs generally required | BSI Online, per the program page | Passing reports within 10 days; failures reported the same day |
| Broomfield City and County of Broomfield | Assemblies in Broomfield's program | BSI Online, $14.95 per report | Reports from testers without current credentials are rejected |
| Golden City of Golden | Assemblies in Golden's program, every year | By email to the city; testers can use their own forms | Service can be terminated for missed testing |
| Lakewood Consolidated Mutual Water or Denver Water | Consolidated Mutual: non-single-family domestic, fire, and irrigation lines. Denver Water areas follow Denver Water's rules | Consolidated Mutual's online portal, by testers who signed its testing agreement | Failures reported within 24 hours, repaired within 10 business days |
| Wheat Ridge Consolidated Mutual, Denver Water, and other districts | Depends on the district: six serve Wheat Ridge, including Consolidated Mutual and Denver Water | Consolidated Mutual's portal, or by email to Denver Water | See your district's notice |
| Englewood City of Englewood | Commercial and multifamily buildings | BSI Online | Tests due Aug. 15; service can be discontinued |
| Commerce City South Adams County Water & Sanitation District | Commercial water users (South Adams County Water & Sanitation) | By email to the district's Backflow Program Office | Reports due Aug. 31 |
| Parker Parker Water & Sanitation District | Commercial, irrigation, and multifamily (4+ units); homes by site hazard such as a pool or hot tub | Parker Water & Sanitation's online tester portal | Failures reported within 1 business day; repaired and retested within 30 days |
| Boulder City of Boulder Utilities | Commercial, industrial, irrigation, fire, and multi-unit lines; most single-unit homes exempt | The city's online backflow portal, within 10 days of the test | $59 hangtag, $113 shut-off fee, penalties up to $1,500 |
| Louisville City of Louisville | Commercial, non-single-family residential, industrial, institutional, and irrigation | BSI Online; the tester pays the filing fee | Tests due Sept. 30 |
| Lafayette City of Lafayette | Non-single-family residential and commercial accounts | BSI Online only | Irrigation due May 31, domestic and fire Aug. 31; $250 per untested assembly |
| Centennial ECCV, ACWWA, Willows Water, or Southgate | Depends on the district: ECCV, ACWWA, Willows Water, or Southgate | ACWWA and Willows by email; ECCV within 10 days of the test; Southgate to Denver Water | ACWWA penalties from $250 after a 60-day notice; Willows rejects late reports |
| Greenwood Village Southgate Water and Sanitation District | Southgate customers (parts of Greenwood Village, Centennial, and Lone Tree west of I-25) follow Denver Water's rules | Emailed to Denver Water on its test report form | Southgate can shut off service; Denver Water's $250 penalty after three unanswered notices |
Summarized from each provider's published program information, checked October 2026. Follow the dates on your own notice; providers update their programs.
What about single-family homes?
Most programs focus on commercial, industrial, multi-family, irrigation, and fire services. Single-family homes are usually brought in when there's a specific hazard, such as a well or pond, a pool or hot tub, or a dedicated irrigation or fire line, and some providers include residential sprinkler systems. The simple rule: if your water provider sent you a backflow notice, your assembly is in the program and the test is required.
Got a notice? Here's what to do
- Find the due date and any code on the notice. Arvada, for example, prints a letter code your tester uses to file the test.
- Book a certified tester before the due date. Late penalties can be steep: Aurora adds $1,000 once a test is 30 days late, and Denver Water charges $250 after three unanswered notices.
- Make sure the water to the assembly is on, especially for sprinkler systems that were winterized.
- Keep a copy of the report. Some programs, like Northglenn's, require owners to keep reports for years.
Not sure what you have?
Our guide explains how to tell a PVB, DCVA, and RPZ apart, and what each test checks: Which backflow preventer do you have?
Need a test?
Singer Plumbing Co.'s owner is an ABPA-certified backflow tester. First test $95 per device for new customers. We test, tag, and file the report the way your provider wants it. Backflow testing → · Commercial & HOA →
Download this data
The rules on this page are also published as open data for property managers, HOAs, contractors, and anyone building a compliance calendar: CSV · JSON. Each row cites the water provider's own page. Reuse it freely with credit to Singer Plumbing Co. and a link to this guide (CC BY 4.0).
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