Backflow tests come due every year. Get a reminder before yours is due, put it on your calendar, and check your water provider's deadline.
Get a reminder before next year's test
Add a yearly reminder to your calendar
Pick the month your test is usually due. You'll get a calendar event that repeats every year, with an alert two weeks ahead and our number in it. Works with iPhone, Google, and Outlook calendars.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Property managers: every fixed deadline in one calendar
Most providers set each property's due date from its last test or by notice. These are fixed calendar deadlines across the metro, with an alert a month ahead:
- Lafayette irrigation backflow tests due (May 31)
- Englewood backflow tests due (Aug. 15)
- Lafayette domestic and fire backflow tests due (Aug. 31)
- Commerce City (South Adams County W&S) backflow tests due (Aug. 31)
- Louisville backflow tests due (Sept. 30)
Download the deadlines calendar · Commercial and HOA backflow testing →
When is your test due? By water provider
| City | When it's due | How the report is filed |
|---|---|---|
| Denver | 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. | Emailed to Denver Water's Cross-Connection Control office on its test report form. Mail is accepted too. |
| Aurora | Proof of testing is due by the annual due date. Records of tests, repairs, and replacements are due within five working days of the work. | Through Aurora Water's online backflow test portal, by a registered tester |
| Thornton | Before the annual due date. The city's FAQ says annual tests must be submitted no later than 60 days after the original due date. | Online through BSI Online (Backflow Solutions Inc.), which charges a fee for each report |
| Westminster | At installation and every year after, by a certified backflow prevention assembly tester | Online through BSI Online, reported to the city's Cross-connection Control team |
| Arvada | Every year: all backflow prevention assemblies must be inspected and tested annually | In Arvada's online cross-connection testing portal (SAMS), by a tester whose registration the city has approved |
| Northglenn | Passing reports within 10 days of the test. Failed test: notify the city the same day and file the report within 10 days; repair and retest, or replace, within 30 days. | Through BSI Online, per the city's backflow program page |
| Broomfield | Through BSI Online | |
| Golden | Every year | By email to backflow@cityofgolden.net; testers can use their own forms |
| Lakewood | ||
| Englewood | Annual tests by Aug. 15. To get more time, email the city's Extension Request form. | The tester uploads the report to BSI Online (Backflow Solutions, Inc.) |
| Commerce City | All reports by Aug. 31 each year | By email to the district's Backflow Program Office |
| Wheat Ridge | ||
| Parker | Domestic and fire assemblies every year. Irrigation assemblies at seasonal startup. New assemblies within 10 days of installation. | Through PWSD's online Backflow Tester Submission Portal. No filing fee is listed. |
| Boulder | Report within 10 days of the test. Failing tests within 24 hours. | Online only, in the city's backflow portal, by a certified tester with their own login. The paper form isn't required. No filing fee is listed. |
| Louisville | Tested every year by Sept. 30 | Through BSI Online. The tester or testing company pays BSI's filing fee. |
| Lafayette | Irrigation assemblies by May 31. Domestic containment and fire assemblies by Aug. 31. | BSI Online only, by testers registered with BSI |
| Greenwood Village | At installation (within 48 hours of a new install) and every year after. Irrigation assemblies are tested as the water is turned on; Denver Water's irrigation testing season runs May through September. | Emailed to Denver Water's Cross-Connection Control office on Denver Water's test report form |
| Centennial |
Summarized from each provider's published rules, checked October 2026. Your provider's notice has the final word on your due date. All of it side by side, with sources: backflow testing requirements by provider.
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