Is the Backflow Device Mine or the Water Utility's? Where the Boundary Falls
Short answer: if the assembly sits on your side of the meter, it is yours. You pay for the testing, you pay for the repairs, and you are the one the district sends the notice to.
That covers the large majority of properties we work on. The rest of this page is about the exceptions and about how to confirm which one you are, because the terms that decide it — point of delivery, service boundary, containment, isolation — are defined by each purveyor's own ordinance, and Southern California has a great many purveyors.
Where the line usually falls
| Typically the utility's | Typically yours |
|---|---|
| The public main in the street | The service line downstream of the meter or customer shutoff |
| The service line up to the curb stop or meter | The backflow assembly serving the property — domestic, irrigation, and private fire |
| The meter and, in many cities, the meter box or vault | All downstream plumbing and fixtures |
The practical version: find the meter. Ownership generally changes at it or just past it.
Containment vs. isolation
This distinction explains most of the confusion, so it is worth being clear about.
Containment is the assembly near the service connection that protects the public system from your entire site. That is the one your water purveyor tracks and sends notices about.
Isolation devices sit inside the property and protect against a specific hazard — a boiler, a beverage machine, a lab faucet, a chemical feeder. Some districts track these, many do not, and plenty of building owners have no inventory of them at all. They are still your responsibility, and they still matter.
Common situations
Curbside meter, irrigation device on the property
The most common residential and small commercial arrangement. The utility owns the main and the meter; the assembly downstream is yours to test and maintain.
Commercial building with a meter vault at the right of way
The utility often owns the vault and meter. The containment assembly is usually just downstream, in an exterior enclosure or a mechanical room, and it is yours — unless the district has installed and tagged its own device in the vault, which is uncommon around here.
A utility-owned containment assembly
A small number of purveyors install and maintain their own containment device at the meter. Where that is the case, they typically test that one device. You are still responsible for every isolation device inside the property. This is exactly the situation to get confirmed in writing, because assuming it either way is expensive.
Private fire service
The private fire line and its assembly — usually a DCDA or RPDA — are the property owner's responsibility even when the utility owns the meter. Fire assemblies also need coordination with your fire protection contractor, since testing means taking the fire service out of play briefly and most jurisdictions want notification first.
Construction hydrant meters
The contractor supplies an approved RP between the hydrant meter and the hose, and the contractor is responsible for its condition and testing while it is in use.
Multi-tenant buildings and HOAs
The owner or association generally holds responsibility for common-area assemblies, and leases sometimes push tenant-specific isolation devices onto tenants. Whatever the lease says, the district holds the account holder or property owner responsible when a test is missed. Worth reading the lease language before you need it.
Get it in writing. Email your purveyor's cross-connection control program and ask them to confirm, per device, who owns it and who tests it. It takes one email and settles the question permanently.
Who pays for what
Testing is on the customer, annually or on whatever cycle your district sets. The report has to reach the purveyor in the format they accept, which around here might mean SwiftComply, BSI, KloudGin, or a PDF emailed to one specific person.
Repairs and rebuilds are on the customer. So are replacements when a device is obsolete, damaged, undersized, or failing repeatedly, along with any permitting that comes with it.
Where a utility owns a specific containment assembly, they typically cover that one device. Everything else on the property is still yours.
Why it is worth pinning down
Missed tests escalate. The usual path is a reminder, a second notice, then enforcement, which at most purveyors can reach shutoff. If backflow from a property contaminates the public system, the liability question turns on who was responsible for maintaining the assembly — which is a bad time to discover nobody was sure.
The properties that never have this problem all do the same thing: they keep one list. Device location, make, model, size, serial number, purveyor, and last test date. One person owns the list. That is the entire trick.
Common questions
Where exactly is the ownership boundary?
Usually the meter or the customer shutoff. Your purveyor's definition of point of delivery is what controls.
Landlord or tenant?
Depends on the lease, but the district will hold the account holder or owner responsible if a test is missed.
I cannot find my device.
Check near the point of entry, mechanical rooms, meter vaults, and irrigation boxes. If it is a larger property, a site survey is faster than hunting for it one notice at a time.