Backflow Laws: Idaho
Idaho Backflow Prevention Laws, Regulations, and Compliance Requirements
Idaho's backflow prevention requirements are established in IDAPA 58.01.08 — Idaho Rules for Public Drinking Water Systems — at Section 552.06, administered by the Idaho Department of Environmental Quality (IDEQ). Idaho maintains a state-issued Backflow Assembly Tester (BAT) license system under Idaho Code § 54-2403 through the Idaho Board of Drinking Water and Wastewater Professionals. This guide covers Idaho's state regulatory framework, the BAT licensing system, the significant 2018 change prohibiting DCVA on irrigation systems, and programs in Boise, Meridian, Nampa, Eagle, Moscow, and other Idaho communities.
Idaho State Regulatory Framework
Idaho’s backflow prevention requirements are established in the Idaho Rules for Public Drinking Water Systems at IDAPA 58.01.08, specifically Section 552.06 — Cross-Connection Control. These rules require every community water system in Idaho to have a cross-connection control program with regular inspections, defined enforcement methods, and annual testing of all installed backflow prevention assemblies. IDEQ holds EPA primacy under the federal Safe Drinking Water Act.
Idaho Code Chapter 54-24 establishes the licensure framework for Backflow Assembly Testers. Under § 54-2403, a ‘backflow assembly tester’ means a person who tests backflow prevention assemblies and holds a current Idaho Backflow Assembly Tester (BAT) license. Only Idaho-licensed BATs may perform tests and submit results to water systems in Idaho. The Idaho Professional Licensing Agency (IPLA) maintains the BAT license database, and the Idaho Board of Drinking Water and Wastewater Professionals oversees the credential.
Cross-connection control programs under Idaho law must include: an inspection program to locate cross-connections; procedures to require and enforce installation of approved assemblies; annual testing requirements; record-keeping requirements; and enforcement authority (typically including water service termination for non-compliance). Section 552.06 cross-references the AWWA Recommended Practice for Backflow Prevention (M14) as a technical guidance resource.
Idaho's 2018 Plumbing Code Change — DCVA Prohibited on Irrigation
A significant change in Idaho plumbing code took effect May 1, 2018: Double Check Valve Assemblies (DCVA) may no longer be installed on lawn irrigation sprinkler systems in Idaho. All new irrigation backflow prevention must use RPZ (Reduced Pressure Zone) assemblies. DCVAs installed prior to the 2018 code change do not need to be immediately removed unless they can no longer be repaired. However, any replacement assembly must meet the current standard — an RPZ. This change has substantial practical implications: Meridian, for example, explicitly prohibits cross connections (dual connections) for residential use and requires removal of any pre-existing dual connections.
Idaho BAT License Requirements
Idaho BAT licensure requires completion of an approved training course and passing a written examination. The Idaho Professional Licensing Agency’s website at pla.IN.gov — wait, this is the Indiana site; Idaho BAT verification uses the Idaho Professional Licensing Agency site. License verification can be done through IDEQ or IPLA. Importantly, the IDEQ notes that Idaho BAT licenses do not expire in the traditional sense — the ‘expiration date’ shown on IPLA’s website refers only to when the next ‘Active’ list questionnaire will be sent to testers, not when their authority to test expires. BATs wishing to be on IDEQ’s ‘Active’ list (useful for utilities and property owners finding testers) must complete the IDEQ questionnaire.
For fire suppression system backflow assemblies, Idaho BATs must hold an additional certification specific to fire protection systems. Municipalities such as Moscow specifically note: ‘Assemblies on fire suppression systems must be tested by BATs certified to work on those systems.’
Annual Testing Deadlines Vary by Municipality
Idaho has no uniform statewide annual testing deadline. Instead, each water system or municipality sets its own deadline. In Moscow, Idaho: irrigation assemblies must be tested within ten business days of spring start-up, no later than June 30th; all other assemblies by September 30th. In Eagle, Idaho: testing notices are mailed approximately 30 days before the due date. Failure to test by the specified due date triggers notices and ultimately service termination. Confirm your specific utility’s annual testing deadline each year.
Idaho's Decentralized Deadline Structure
Idaho water systems set their own annual testing deadlines — there is no uniform June 30th or December 31st deadline across the state. Irrigation backflow assembly deadlines are often set at spring startup (June 30th in Moscow, for example), while non-irrigation assemblies may have September or December deadlines. Property managers with multiple Idaho properties may have different deadlines for each water system. Confirm your specific utility’s due dates at the start of each calendar year.
Major Water Purveyors in Idaho
Boise City Utilities
The City of Boise provides water service to Idaho’s capital city. Boise’s cross-connection control program is aligned with IDAPA 58.01.08 Section 552.06. Annual testing by Idaho-licensed BATs is required. Test reports must be submitted to the City of Boise within the city’s specified deadlines. Boise requires USC-approved assemblies for all covered connections.
City of Meridian Public Works
Meridian is one of the fastest-growing cities in the nation and has an active cross-connection control program. Meridian’s program explicitly prohibits cross connections (dual connections) for residential use — if a residential cross connection exists, it must be removed. The 2018 DCVA prohibition on irrigation systems applies fully in Meridian. All irrigation systems must have RPZ assemblies. Annual testing by Idaho-licensed BATs is required with results submitted to the city.
City of Nampa
Nampa’s utilities serve Idaho’s second-largest city in Canyon County. Nampa’s cross-connection control program requires annual testing for all covered commercial and residential irrigation assemblies. RPZ assemblies are required for all irrigation systems under the post-2018 plumbing code requirements.
City of Eagle
Eagle, Idaho has been particularly active in enforcing its cross-connection control program. The City sends testing notices approximately four weeks before the annual due date. Non-compliant properties receive follow-up notices and ultimately face service termination. Eagle requires both external assemblies (protecting the city’s water from property-side cross-connections) and internal assemblies (protecting the customer from hazards within their own system) where applicable. Eagle explicitly states: ‘If your property has outside water sources connected to your potable water, you are required by the State of Idaho to have the proper backflow assembly in use and to have it tested annually.’
City of Moscow (Latah County)
Moscow operates one of the most programmatically detailed cross-connection control programs in Idaho. Key specifics: irrigation assemblies must be tested within ten business days of spring start-up and no later than June 30th; all other assemblies must be tested by September 30th. The Public Works Director has authority to modify test due dates. DCVA assemblies can no longer be installed on lawn irrigation systems (2018 code change). Notifications are mailed approximately four weeks before the due date. Moscow accepts USC-approved assemblies only.
Coeur d'Alene, Twin Falls, and Other Idaho Communities
Coeur d’Alene (Kootenai County), Twin Falls, Caldwell, Post Falls, Rexburg, Idaho Falls, and Pocatello each operate cross-connection control programs aligned with IDAPA 58.01.08. Annual testing is standard across all programs. The 2018 DCVA prohibition on irrigation systems applies statewide. Each city’s specific deadlines, approved tester lists (all must be Idaho-licensed BATs), and test result submission procedures should be confirmed directly with each utility.
Pre-2018 DCVA on Irrigation — What to Do
If your property has a DCVA installed on an irrigation system prior to May 1, 2018, Idaho does not require immediate removal under the 2018 code change — but the device cannot be replaced with another DCVA when it fails. When the existing DCVA can no longer be repaired (worn rubber goods, cracked body, failed test that cannot be corrected by rebuild), it must be replaced with an RPZ. Budget for this replacement when planning irrigation system maintenance for older properties.
Property Owner Compliance Summary for Idaho
BAT licensing: Testing must be performed by an Idaho-licensed Backflow Assembly Tester only.
Irrigation: All lawn irrigation systems require RPZ assemblies (not DCVA) per the post-2018 Idaho Plumbing Code.
Fire systems: Fire suppression assembly testing requires a BAT with additional fire system certification.
Annual deadlines: Confirm your specific municipality’s annual testing deadline. Do not assume uniformity across Idaho utilities.
Filing: Results submitted to your water utility within their specified window.
Records: Retain all test reports. Provide to the utility and IDEQ on request.
Find a Certified Backflow Tester in Idaho
Find Idaho-licensed BATs at getyourbackflowtested.com/backflow-testing-near-me/idaho-backflow-testing — covering Boise, Meridian, Nampa, Eagle, Coeur d’Alene, and all major Idaho communities. Verify license status through the Idaho Professional Licensing Agency.
Idaho Regulatory Reference Links
| Resource / Agency | URL / Link Target |
|---|---|
IDEQ — Cross-Connection Control | |
IDAPA 58.01.08 — Idaho Rules for Public Drinking Water Systems | |
Idaho Code § 54-2403 — Backflow Assembly Tester Definition | |
Idaho Professional Licensing Agency — BAT License Lookup | |
City of Eagle — Backflow Prevention and Testing | |
City of Moscow — Cross-Connection Control Program | |
Idaho Rural Water Association — Cross Connections |