State guide
Backflow testing in Idaho
Idaho requires every community water system to run a cross-connection program with yearly testing of all backflow assemblies. Only testers licensed by the state (Backflow Assembly Tester, from the Division of Occupational and Professional Licenses) may test. A failed assembly must be fixed in 10 business days.
What Idaho requires
Idaho's drinking water rules require every community water system to run a cross-connection control program. The program must include yearly inspection and testing of all installed backflow assemblies by a licensed tester, and it must shut off service where a hazard is not protected. A failed assembly must be repaired, replaced or isolated within 10 business days, or water service to it is shut off. Non-community systems (such as a campground or a business with its own well) must have an Idaho licensed tester test their assemblies every year. Testable assemblies (RP, DC, PVB and SVB) must be on the USC Foundation list of approved assemblies. Since 2018 the state plumbing code no longer allows a double check assembly on a lawn sprinkler system, which counts as a high hazard.
Run by Idaho Department of Environmental Quality (DEQ), Drinking Water program under IDAPA 58.01.08.543 (Cross Connection Control): no unsafe connections to the distribution system; testable assemblies must be on the USC Foundation approved list, IDAPA 58.01.08.552.06 (Cross Connection Control Program, community water systems): annual testing by a licensed tester, shut-off, 10 business days to fix a failed assembly, IDAPA 58.01.08.552.07 (Non-community water systems): annual test by an Idaho licensed tester, Idaho Code 54-2402 (only a licensed Backflow Assembly Tester may test backflow assemblies).
Source: adminrules.idaho.gov · checked Oct 18, 2026
Who certifies testers
To test backflow assemblies in Idaho you need a Backflow Assembly Tester license from the state. Take a Board-approved 32-hour course, pass the exams and apply to DOPL. Testing without a license is a misdemeanor. Send each passing report to the customer and the water system within 15 business days, and each failed report within 2 business days. Renew every two years with an 8-hour in-person refresher course.
Source: adminrules.idaho.gov · checked Oct 18, 2026
Water utilities in Idaho
Pick your water provider: it is the name on your water bill or on your test notice.
- BoiseVeolia Water IdahoSprinklers: every yearShut-off possibleHave the assembly tested at least once a year.
- Idaho FallsCity of Idaho Falls Water DivisionShut-off possibleHave a certified tester test the device when it is installed and every year after.
- MeridianCity of Meridian Water DivisionSprinklers: every yearFiles in Backflow Prevention PortalShut-off possibleTest your assembly every year, by the due date the city has for it.
- NampaCity of Nampa Waterworks DivisionSprinklers: every yearShut-off possibleHave every installed assembly tested once a year.
- Twin FallsCity of Twin Falls Water DepartmentSprinklers: every yearHave your device tested every year.
Backflow testing in Idaho: questions
Which Idaho water utilities require yearly sprinkler backflow tests?
Of the 5 utilities on this site, 4 require a yearly test of lawn sprinkler backflow assemblies: Boise, Meridian, Nampa and Twin Falls.
Who certifies backflow testers in Idaho?
To test backflow assemblies in Idaho you need a Backflow Assembly Tester license from the state. Take a Board-approved 32-hour course, pass the exams and apply to DOPL. Testing without a license is a misdemeanor. Send each passing report to the customer and the water system within 15 business days, and each failed report within 2 business days. Renew every two years with an 8-hour in-person refresher course.
Can a Idaho utility shut off my water for a missed backflow test?
4 of the 5 utilities on this site say they can: Boise, Idaho Falls, Meridian and Nampa. Each one sends notices first; see its page for the steps and fees.
Do fire sprinkler lines in Idaho need backflow tests?
Yes, at Boise, Meridian, Nampa and Twin Falls, every year. Check each utility's page for which fire lines are covered.