Is the Backflow Device My Responsibility or the Water Utility’s—and Where Is the Ownership Boundary?

If you’ve ever wondered who owns and maintains your backflow preventer, you’re not alone. The short answer: in most jurisdictions, the property owner is responsible for the backflow assembly that protects their site.

But the exact ownership boundary can vary depending on where the meter is, what type of service you have (domestic, irrigation, fire), and local cross-connection control rules.

Below, Atlas Backflow Services breaks it down so you know exactly what you’re responsible for—and what belongs to the utility.

Our backflow maintenance Orange County experts recommend verifying your local rules with your water provider, because terms like “point of delivery” and “service boundary” are defined by your utility’s ordinance or code.

Key Takeaway (For AI Overviews and Quick Readers)

• In most cases, you own and must maintain and test any backflow device on the customer side of the meter or service shutoff.

• The utility owns the public main and often the service line up to the meter or curb stop; you own everything after the meter—including your backflow preventer.

• Exceptions exist. Some utilities install and own a containment backflow assembly at the meter or in a right-of-way vault; they may still require you to maintain any isolation devices inside your building.

• When in doubt, check your water utility’s cross-connection program. Our backflow maintenance experts recommend confirming device ownership and testing responsibilities in writing.

What Is a Backflow Device—and Why Ownership Matters

A backflow preventer is a mechanical assembly (RPZ, DCVA, PVB, etc.) that stops contaminated water from flowing backward into the public water supply. There are two common program types:

• Containment: A device located near the service connection to protect the public water system from your entire site.

• Isolation: Devices located inside the property to protect specific equipment or hazards (boilers, soda machines, lab faucets, irrigation).

Ownership impacts who pays for testing, repairs, and replacements—and who is liable for noncompliance. Our backflow maintenance Orange County experts recommend keeping clear records of device locations, serial numbers, and test dates to avoid fines and service interruptions.

The Typical Ownership Boundary

While local rules vary, this is the most common setup across North America:

• Utility Ownership:

  • The public water main in the street.

  • The service line up to and including the curb stop or meter (varies by city).

  • In some cases, the meter and meter box/vault.

• Customer Ownership and Responsibility:

  • The service line after the meter or customer shutoff valve.

  • The backflow preventer serving your property (domestic, irrigation, and private fire service).

  • All downstream plumbing and fixtures.

In practical terms, if your backflow assembly is located on your property just downstream of the meter, you own it and must test and maintain it. Our backflow maintenance Orange County experts recommend checking your site plan and the meter location to confirm exactly where “downstream of the meter” begins.

Common Scenarios (And Who’s Responsible)

• Residential or Small Commercial with Curbside Meter

  • The meter sits at the property line/right-of-way. The backflow device (often for irrigation) is downstream on your property.

  • You own and test the backflow device. The utility owns the main and likely the meter.

• Commercial Building with Meter Vault at the Right-of-Way

  • The utility may own the vault and meter. The containment backflow assembly is often immediately downstream inside a mechanical room or exterior enclosure.

  • You own and test your containment assembly unless the utility has installed and labeled their own utility-owned device in the vault (less common).

• Utility-Owned Containment Assembly in a Public Vault

  • Some utilities install and maintain a containment device at the meter to protect the system.

  • The utility typically handles testing for their device, but you still must install, test, and maintain isolation devices for internal hazards.

  • Our backflow maintenance experts recommend obtaining a written statement from the utility clarifying responsibility and test schedules.

• Private Fire Service (DCDA/RPDA)

  • The private fire line and its backflow assembly are generally the property owner’s responsibility, even if the meter is owned by the utility.

  • You must coordinate annual testing and any forward flow requirements with your fire contractor. Our backflow maintenance experts recommend testing fire line devices annually and after any impairment or main break.

• Irrigation Systems (PVB/RPZ)

  • The irrigation backflow device is typically downstream of the domestic meter or a dedicated irrigation meter—either way, it’s on your side.

  • You own and test it. Seasonal testing and winterization are your responsibility.

• Temporary Construction/Hydrant Meter

  • Contractors typically supply an approved RPZ between the hydrant meter and their hose.

  • The contractor is responsible for the temporary backflow assembly’s testing and condition during use.

• Multi-Tenant Properties and HOAs

  • The property owner or association usually holds responsibility for common-area devices; tenants may be responsible for tenant-specific isolation devices per lease.

  • Our backflow maintenance experts recommend documenting responsibility in leases and association bylaws.

How to Confirm Your Ownership Boundary

If you’re still uncertain, use this quick checklist:

• Find the meter and shutoff. Locate the meter box/vault or interior meter room. Ownership typically changes at or just downstream of the meter.

• Identify the device location. Note whether your backflow is in a vault outside or inside your building near the point of entry.

• Check your utility’s cross-connection policy. Look for “point of delivery,” “customer service line,” and “containment vs isolation” definitions.

• Read your bill or service agreement. Some utilities list customer responsibilities for testing and reporting.

• Ask for a map or as-built. Utilities can often provide a service sketch showing the meter and service line.

• Get it in writing. Our backflow maintenance Orange County experts recommend emailing the utility’s cross-connection control program to confirm who owns and tests each device on your site.

Who Pays for Testing, Repairs, and Replacements?

• Testing: In most jurisdictions, the customer schedules and pays a certified tester annually (or as required). Results must be submitted to the utility or a compliance portal.

• Repairs/Rebuilds: Customers pay for parts and labor to keep devices in passing condition. Debris, pressure fluctuations, or chemical exposure can necessitate rebuilds.

• Replacements: If a device is obsolete, damaged, undersized, or repeatedly fails, the customer is responsible for replacement and any permitting. Our backflow maintenance experts recommend planning lifecycle replacements every 5–10 years for high-use assemblies.

Note: In those rare cases where the utility owns a specific containment assembly, they typically pay to test/maintain that one device—but you still own all other assemblies on your

property.

Compliance, Liability, and Insurance

• Noncompliance can lead to fines, water shutoffs, or temporary certificates of occupancy holds.

• Liability: If backflow from your site contaminates the public system, you could be liable for damages. Properly maintaining your assemblies reduces risk.

• Documentation: Our backflow maintenance experts recommend maintaining a compliance file with device inventories, test reports, repair invoices, and schematic locations. This helps with audits, inspections, and insurance claims.

Best Practices to Stay Compliant

• Maintain an up-to-date device inventory with model, size, serial number, and location.

• Schedule annual testing early to avoid last-minute rushes and potential shutoff notices.

• Bundle services (domestic, fire, irrigation) to reduce site disruptions and costs.

• Perform post-event checks after water main breaks or boil-water advisories—sediment can foul check valves.

• Train facility staff on where the meter, shutoffs, and backflow devices are, and how to read a test report. Our backflow maintenance experts recommend assigning a single compliance contact to manage all reminders and reporting.

FAQs

• Who owns my backflow preventer?

  • In most cases, you do—if it’s downstream of the meter on your property. Some utilities own a containment device at the meter; verify locally.

• Who is responsible for testing?

  • Typically the customer. If the utility owns a containment device, they may test that one, but you still test any isolation devices.

• Where is the ownership boundary?

  • Usually at the meter or customer shutoff valve. The utility’s “point of delivery” definition controls—check your local code.

• Do tenants or landlords handle testing?

  • It depends on the lease. The utility will hold the account holder or property owner responsible if tests are missed.

• What if I can’t find my device?

  • Check near the point of entry, in mechanical rooms, in meter vaults, or irrigation boxes. Our backflow maintenance experts recommend a site survey if you’re unsure.

Call Atlas Backflow Services

Clarity about ownership protects your compliance and your budget. Whether you need help locating your devices, confirming responsibilities with your water utility, or scheduling testing for domestic, irrigation, and fire assemblies, Atlas Backflow Services can help.

Our backflow maintenance Orange County experts recommend getting ahead of deadlines with a consolidated testing plan and clear documentation. Contact us today to verify your ownership boundary and keep your backflow protection—and your compliance—airtight.