City water utility · Idaho
Backflow testing in Nampa, ID
City of Nampa Waterworks Division's rules: who must test, when it's due, testers, filing and penalties.
Nampa requires backflow assemblies on businesses, fire sprinkler systems and lawn sprinklers on city water, tested every year by a city-approved, Idaho-licensed tester at your cost. The tester sends results to the city. Missed tests can lead to a water shut-off and a fine up to $300.
- Who
- Lawn sprinkler systems: every year
- Businesses: every year
- Fire sprinkler lines: every year
- Due
- Have every installed assembly tested once a year.
- Testers
- City of Nampa Waterworks Division's list (PDF)
- Filing
- Your tester files. No filing fee listed.
- If late
- Water can be shut off.
Who must have a backflow test
Every backflow assembly installed on Nampa city water must be inspected and tested once a year by a tester the city has approved, at the customer's cost. The results go to the city. The city can require testing more often where the hazard is higher.
- Lawn sprinkler systemsRequiredannual inspection and testing of all installed assemblies
Lawn sprinkler systems need a reduced pressure (RP), pressure vacuum breaker (PVB) or spill resistant (SVB) assembly. If you water with city drinking water because no pressure irrigation is available, you also need a separate meter and a backflow device that a licensed Idaho backflow specialist certifies every year.
- BusinessesRequiredannual inspection and testing of all installed assemblies
Every industrial and commercial building needs at least a double check (DC) assembly on its water service, or a stronger one where the hazard is higher.
- Fire sprinkler linesRequiredannual inspection and testing of all installed assemblies
Wet and dry fire sprinkler systems need a double check assembly. Systems with chemicals or an antifreeze loop need an RP assembly.
Assemblies tested: Reduced pressure assembly (RP or RPZ), Double check valve assembly, Pressure vacuum breaker, Spill-resistant vacuum breaker. What these are
Source: library.municode.com · checked Oct 18, 2026
When the test is due
Have every installed assembly tested once a year. Call the Cross Connection Program to find out when yours is due. A new building must pass the city's cross connection inspection before water service starts.
Source: library.municode.com · checked Oct 18, 2026
Finding a tester
Choose a tester from the city's approved tester list. Your tester must be licensed by the State of Idaho and must keep proof of insurance and test kit calibration on file with the city. You can check a license on the state's license search.
Source: library.municode.com · checked Oct 18, 2026
Filing the test report
- Who files
- Your tester
- Deadline
- Test results must be submitted by the 1st of the month after the test
- Fee
- None listed by the utility
Testers tag each assembly they test with a permanent tag showing their license number and the test date. A first test of a new assembly also needs a survey sheet. Testers must report improper installations to the city. Call the program to ask how to send reports.
Source: cityofnampa.us · checked Oct 18, 2026
If the test is late or fails
Failing to install, maintain, inspect and test a required assembly, or refusing access to check for cross connections, is grounds to end your water service. Service resumes only when you fully comply. A violation is a misdemeanor with a fine up to $300 or up to six months in jail, or both. Each day counts as a separate violation. For an irrigation device that is not certified every year, the city can also end service, or repair or replace the device and bill the owner.
Failed test: State rules give 10 business days to repair, replace or isolate an assembly that fails its test. If that cannot be done in time, water service to it must be shut off.
Rule: Nampa City Code § 8-5-6 (Violations and penalties); § 8-1-22 (irrigation water)
Source: library.municode.com · checked Oct 18, 2026
For testers working in Nampa
Testers must register with City of Nampa Waterworks Division before their reports are accepted.
- Idaho backflow assembly tester license, licensed or recertified within the past 24 months
- At least $500,000 liability insurance, with proof on file with the city
- Test equipment recalibrated within the past 12 months, with the certificate on file with the city
- Permanent tag on each tested assembly with license number and test date
- Threaded plug on test cocks of underground double check assemblies
- Report improper installations to the city
- Survey sheet for the first test of a new assembly
- Test results submitted by the 1st of the month
To be on the city's approved tester list, sign the city's Tester List of Requirements and Agreement with your license number, and keep your proof of insurance and your latest test kit calibration certificate on file with the program. Call the program to confirm the current steps. A tester who turns in false test results is banned from testing in Nampa for six months, and permanently after a second offense.
Source: cityofnampa.us · checked Oct 18, 2026
The rules behind it
- Nampa City Code Title 8, Chapter 5 (Cross Connection Program), sections 8-5-4 to 8-5-6: Sets yearly testing at the customer's cost, tester proof requirements, grounds for ending service, the fine and the ban for false test results.
- Nampa City Code § 8-1-22 (Waste of irrigation water): Lets the city end service or fix the device at the owner's cost if an irrigation backflow device is not certified every year.
- IDAPA 58.01.08.552.06 (Cross Connection Control Program, community water systems): A failed assembly must be repaired, replaced or isolated within 10 business days, or service is shut off.
Contact City of Nampa Waterworks Division
- Program
- Cross Connection Program
- Phone
- 208-468-5504
Source: cityofnampa.us · checked Oct 18, 2026
Backflow testing in Nampa: questions
Do I need a backflow test for my sprinkler system in Nampa?
Yes. City of Nampa Waterworks Division requires backflow assemblies on lawn sprinkler systems to be tested annual inspection and testing of all installed assemblies. Lawn sprinkler systems need a reduced pressure (RP), pressure vacuum breaker (PVB) or spill resistant (SVB) assembly. If you water with city drinking water because no pressure irrigation is available, you also need a separate meter and a backflow device that a licensed Idaho backflow specialist certifies every year.
When is my backflow test due in Nampa?
Have every installed assembly tested once a year. Call the Cross Connection Program to find out when yours is due. A new building must pass the city's cross connection inspection before water service starts.
How do I find a backflow tester in Nampa?
Choose a tester from the city's approved tester list. Your tester must be licensed by the State of Idaho and must keep proof of insurance and test kit calibration on file with the city. You can check a license on the state's license search.
Who sends the backflow test report to City of Nampa Waterworks Division?
Your tester files the test report, Test results must be submitted by the 1st of the month. Testers tag each assembly they test with a permanent tag showing their license number and the test date. A first test of a new assembly also needs a survey sheet. Testers must report improper installations to the city. Call the program to ask how to send reports.
What happens if I skip my backflow test in Nampa?
Failing to install, maintain, inspect and test a required assembly, or refusing access to check for cross connections, is grounds to end your water service. Service resumes only when you fully comply. A violation is a misdemeanor with a fine up to $300 or up to six months in jail, or both. Each day counts as a separate violation. For an irrigation device that is not certified every year, the city can also end service, or repair or replace the device and bill the owner.
What if my backflow assembly fails the test?
State rules give 10 business days to repair, replace or isolate an assembly that fails its test. If that cannot be done in time, water service to it must be shut off.
Every fact on this page comes from City of Nampa Waterworks Division's own pages, forms or code, checked Oct 18, 2026. Rules change: your notice and the utility have the final word. Spot a mistake? Tell us.