Backflow News
North Carolina Reduces Residential Irrigation Backflow Testing to Every Three Years Under Session Law 2024-49
North Carolina made one of the most property-owner-friendly regulatory changes in the national backflow prevention landscape in 2024, when the legislature passed Session Law 2024-49 — incorporating provisions from Senate Bill 166 — that reduced the required testing frequency for residential irrigation backflow preventers from as often as every two years to no more frequently than once every three years. The change affected property owners across North Carolina, triggering a wave of utility ordinance updates and compliance calendar adjustments throughout 2024 and 2025.
What Session Law 2024-49 Actually Did
The law amended North Carolina General Statute 130A-330 — the statute governing local authority to require backflow preventers — to prohibit any public water system owned or operated by a local government unit from requiring periodic testing more frequently than once every three years for backflow preventers on residential irrigation systems that do not apply or dispose of chemical feeds. The key qualifier is critical: the triennial testing limitation applies only to residential irrigation systems with no chemical feed capability. Any residential irrigation system with chemical injection, fertilizer application, or pesticide dosing equipment does not qualify for the three-year cycle and remains subject to the utility’s standard testing frequency, which for most North Carolina utilities is annual.
The law also provided civil liability immunity for public water systems and their employees — including the Cross-Connection Control Operator in Responsible Charge — for the limitations on periodic testing. This immunity provision addresses the concern that a utility reducing its testing frequency requirement might face liability if a reduced-frequency assembly subsequently failed and caused a contamination event. The immunity applies specifically to the decision to limit testing to the triennial schedule — utilities are not immune from liability for other aspects of their cross-connection control programs.
Additionally, the law updated definitions to formalize a ‘certified backflow prevention assembly tester’ as a defined term in North Carolina statutes, and it clarified that public water systems may accept test results from plumbing contractors licensed under Article 2, Chapter 87, in addition to certified backflow prevention assembly testers approved by the system.
How Utilities Are Implementing the Change
The practical implementation of the triennial residential irrigation testing schedule varied across North Carolina utilities, as each had to revise its own cross-connection control ordinance and compliance calendar. OWASA (Orange Water and Sewer Authority, serving Chapel Hill, Carrboro, and Hillsborough) revised its Cross-Connection Control Manual in both November 2024 and August 2025, and updated its Cross-Connection Control Ordinance in August 2025. Under OWASA’s implementation, backflow assemblies on irrigation systems that remain in service year-round with no chemical feeds or booster pumps may be tested once every three years. However, OWASA requires annual certification that no chemical feed is present, and if the backflow assembly is removed for winterization, testing within 10 days of reinstallation is required regardless of where the property falls in the three-year cycle.
The Town of Apex’s implementation is among the most detailed. Apex updated its Cross-Connection Control Ordinance on February 11, 2025, and notified residential irrigation customers via mail the week of May 12, 2025. Under Apex’s program, residential irrigation customers’ test due dates are staggered by geographical area and set to July 31st of the assigned test year. After a test is submitted in the given year through the AquaResource portal, the due date automatically updates to July 31st three years in the future. If a backflow preventer requires repair or replacement between scheduled test years, a test is still required following repair — but this repair-triggered test does not reset the three-year due date unless it falls within 105 days of the next scheduled due date.
Brunswick County Utilities noted that residential irrigation testing requirements shifted to every three years as of September 2024, with commercial irrigation systems continuing to require annual testing. Many North Carolina utilities continue to roll out the three-year cycle to their residential irrigation customer base through 2025.
What This Means for North Carolina Property Owners
If you own a residential property in North Carolina with a lawn irrigation system that does not have chemical injection capability, you are very likely now subject to a triennial — every three years — backflow testing schedule rather than the annual or biennial schedule that previously applied. Contact your specific water utility to confirm your assigned test year and due date. Do not assume you are off the hook for testing — the due date still exists, it is simply further out on the calendar. And if your irrigation system has any chemical feed capability — fertilizer, pesticide, or other additive injection — the three-year schedule does not apply to you. Annual testing continues to be required for all commercial backflow assemblies across North Carolina regardless of the residential irrigation change.
North Carolina Triennial Testing — Key Conditions That Must Be Met
The three-year testing cycle for residential irrigation backflow preventers applies ONLY when: (1) the property is residential (not commercial); (2) the irrigation system does not apply or dispose of chemical feeds; and (3) if the assembly is removed for winterization, it must be tested within 10 days of reinstallation. If any of these conditions are not met, annual testing requirements continue to apply. Confirm your specific requirements with your water utility — each NC utility’s ordinance may have additional conditions.
Source: NC General Assembly Session Law 2024-49 — LRS Bill Summary; OWASA Cross-Connection Control Manual August 2025 revision; Town of Apex Cross-Connection Control Program (February 2025 ordinance revision, May 2025 customer notification); Brunswick County Utilities Cross-Connection Control program page. Published at getyourbackflowtested.com/backflow-news