Backflow testing for lawn sprinklers, by city
A lawn sprinkler system connects to drinking water, so it needs a backflow preventer to stop fertilizer and lawn water from being pulled back into the pipes. Most cities require that device to be tested by a certified tester, usually every spring, with the report filed by a set date. Miss it and you can face late fees or a water shutoff notice.
14 cities and utilities in 9 states, each checked against official sources in November 2026.
| City | Rule | Key detail | Status |
|---|---|---|---|
| Colorado Springs, CO | Licensed plumbers (HB24-1344), or certified cross-connection technicians in Colorado Sprin | Since July 2024, Colorado law HB24-1344 requires backflow testing, inspection and repair to be done by license | Test every year |
| Geneva, IL | At installation, then every year. | Geneva requires residential irrigation backflow devices to be tested when installed and every year after | Test every year |
| South Holland, IL | May 31 each year. | South Holland requires residential lawn irrigation backflow devices to be tested on or before May 31 every yea | Test every year |
| Bel Aire, KS | Every even-numbered year. | Bel Aire requires backflow devices to be tested every even-numbered year. | Test every 2 to 3 years |
| O'Fallon, MO | June 1. | O'Fallon, Missouri requires annual backflow tests on irrigation systems, with reports due June 1 | Test every year |
| Wentzville, MO | Test report due June 1. | Wentzville requires every lawn irrigation system to have a backflow preventer tested each year by a Missouri-c | Test every year |
| Apex, NC | Every 3 years for residential irrigation. | Apex tests residential irrigation backflow every three years, with results due by July 31 of your assigned yea | Test every 2 to 3 years |
| Cary, NC | Town-certified backflow technicians, scheduled by the town. | Cary automatically schedules residential irrigation customers for backflow tests done by town-certified techni | Utility runs the test |
| Concord, NH | The city, every year, since July 2025. | Concord began doing annual residential irrigation backflow tests itself in July 2025. | Utility runs the test |
| Gahanna, OH | Within 12 months of the previous test. | Gahanna requires the backflow preventer on a lawn irrigation system to be tested every 12 months after the las | Test every year |
| North Ridgeville, OH | June 15. | North Ridgeville requires annual backflow tests by a certified tester and recommends testing in the spring | Test every year |
| Longview, TX | Every year. | Longview requires yearly backflow tests on irrigation systems, but owners who do not use their sprinklers can | Test every year |
| San Antonio, TX | Every year. | San Antonio Water System requires annual tests of backflow assemblies on lawn irrigation systems and sends rem | Test every year |
| Herriman, UT | Every year, under the Utah Plumbing Code. | Herriman notes that the Utah Plumbing Code requires annual testing of all backflow assemblies, including those | Test every year |
Step by step
- Find the backflow device near where the sprinkler line leaves the house, often a valve assembly above ground.
- Check your city's deadline. Many fall between May 31 and June 15.
- Hire a tester certified in your state, or wait for the utility if it tests for you.
- Make sure the tester files the report with the city, and keep a copy.
- Not using the sprinklers? Ask about an inactive or deactivation certificate instead of a test.
What it costs
A residential backflow test usually costs about $50 to $150. Some cities add a small filing fee, around $12, and late fees can run $30 to about $80. Repairs to a failed device cost more.
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