Who Is Qualified to Install a Backflow Prevention Assembly?

Choosing the right backflow device is crucial—but choosing the right installer is what keeps you compliant, protected, and approved on the first inspection. In the Los Angeles area, licensing, certifications, and water-purveyor rules determine who can legally install backflow prevention assemblies.

Atlas Backflow Services created this guide to help you hire confidently. Where details vary by jurisdiction, our Backflow Testing Los Angeles recommend a quick check with your water purveyor before you schedule work.

Quick Answer

• Domestic/irrigation systems: A California-licensed plumbing contractor (C‑36) should install.

• Fire sprinkler systems: A California-licensed fire sprinkler contractor (C‑16) should install detector assemblies (DCDA/RPDA).

• Initial testing: Must be performed by a certified backflow tester approved by your water purveyor (AWWA/ABPA or equivalent).

• Permits/approvals: Building/plumbing permits and purveyor approval are typically required before installation.

  
  

  For smooth approvals, our Backflow Testing Los Angeles recommend confirming the device type, permit path, and approved tester list with your purveyor (e.g., LADWP) in advance.

Installer vs. Tester: What’s the Difference?

• Installer (Contractor): Installs or replaces the assembly, reroutes piping, adds enclosures/vaults, and provides drainage for RPZ relief valves. In California, this is typically a C‑36 for domestic/irrigation and a C‑16 for fire systems.

• Tester (Certified): Performs the required performance test (after installation and annually) using calibrated equipment, then submits the report to the water purveyor.

Some companies do both. However, a tester certification alone does not authorize someone to perform plumbing or fire sprinkler installation work.

Our Backflow Testing Los Angeles experts recommend hiring a firm that can coordinate both the licensed installation and the certified test to minimize delays.

What Credentials Should You Verify?

Before you sign a proposal, validate credentials. Our Backflow Testing Los Angeles experts recommend verifying the following:

• California CSLB License:

  • C‑36 Plumbing for domestic/irrigation assemblies (RPZ, DCVA, PVB/SVB).

  • C‑16 Fire Protection for fire line detector assemblies (DCDA/RPDA).

  • Active, in good standing, with adequate bonding and insurance. Use the CSLB online lookup.

• Backflow Tester Certification:

  • AWWA (e.g., CA‑NV Section) or ABPA Backflow Prevention Assembly Tester.

  • Purveyor approval/registration (LADWP and neighboring utilities maintain approved tester lists).

• USC FCCCHR Listing Compliance:

  • Device model must be listed by the USC Foundation for Cross-Connection Control and Hydraulic Research, installed per listing and manufacturer specs.

• Local Knowledge:

  • Familiarity with Los Angeles Department of Water and Power Cross-Connection Control requirements, LADBS permitting, and local fire authority processes.

• Safety & Site-Specific Qualifications:

  • Confined-space training for vault work, traffic control if in the right-of-way, hot-work where applicable, and documented QA/QC for gauge calibration.

If any of these are unclear, our Backflow Testing Los Angeles experts recommend requesting proof before work begins.

Why DIY or Handyman Installation Risks Rejection

Backflow assemblies protect public health. Improper installation can contaminate potable water, fail inspections, and void your approvals.

• Code and purveyor alignment: Devices must be the correct type (e.g., RPZ vs. DCVA), elevation, orientation, and location (containment vs. isolation).

• Drainage for RPZs: Relief valves discharge by design; no code-compliant drain means no approval.

• Clearances and accessibility: Testable assemblies require specific access for gauges and shutoff operation.

• Approved materials and methods: Unlisted parts, buried test cocks, or flooded vaults can trigger immediate failure.

  
  

  Our Backflow Testing Los Angeles experts recommend avoiding costly rework by using licensed specialists from the start.

Who Is Qualified in Common Los Angeles Scenarios?

• Residential irrigation (no chemicals): Licensed C‑36 plumber installs a PVB/SVB above the highest downstream outlet; certified tester completes initial test and files with purveyor.

• Irrigation with fertilizer/fertigation: C‑36 installs an RPZ with code-compliant drainage; certified tester verifies performance.

• Commercial kitchens, breweries, salons, labs: C‑36 installs RPZs or specialized devices (e.g., ASSE 1022 for soda carbonators); certified tester reports results to the purveyor.

• Domestic service containment for a commercial building: C‑36 installs a DCVA or RPZ per hazard level and purveyor policy; permits and initial test follow.

• Fire sprinkler backflow: C‑16 installs a DCDA (no additives) or RPDA (with antifreeze/foam); fire authority sign-off plus certified test required.

When in doubt, our Backflow Testing Los Angeles experts recommend choosing the higher level of protection your purveyor allows and confirming the permit path in advance.

What a Qualified Installer Actually Does

A quality installation is more than cutting in a device. Our Backflow Testing Los Angeles experts recommend ensuring your contractor provides:

• Site assessment and device selection confirmation: Verifies hazard classification, elevation constraints, freeze/UV protection, and drainage capacity.

• Permitting and submittals support: Provides cut sheets, USC listings, and location diagrams for plan check and purveyor approval.

• Precise installation: Correct orientation, height, unions for service, isolation valves, support/anchorage, and protection from submergence or impact.

• Startup and coordination: Schedules water shutoffs, minimizes downtime, and coordinates the certified test the same day.

• Documentation: Serial numbers, model, size, initial test report, and maintenance recommendations.

How to Pre-Qualify a Provider (Fast Checklist)

Our Backflow Testing Los Angeles experts recommend asking these five questions:

1. What is your CSLB license classification and number (C‑36 or C‑16)?

2. Are your testers certified by AWWA/ABPA and approved by my water purveyor?

3. Do you handle purveyor submittals and building/fire permits?

4. How do you provide RPZ drainage compliance if installed indoors?

5. Can you share recent Los Angeles references and a sample test report?

If the answers are vague, keep looking.

Common Installation Mistakes Qualified Pros Avoid

• Wrong device for the hazard: Installing a DCVA where an RPZ is required.

• Incorrect elevations: PVB below downstream outlets, or valves too close to grade.

• No drainage plan for RPZs: Relief discharge causing water damage or code violations.

• Insufficient clearances: Test cocks blocked by walls or enclosures.

• Submergence risks: Devices in flood-prone vaults without proper mitigation.

• Skipping initial test submission: Causing compliance notices from the purveyor.

  
  

  Our Backflow Testing Los Angeles experts recommend a pre-install walkthrough to catch these before you buy equipment.

Cost, Timeline, and What to Expect

• Typical timelines:

  • Residential irrigation: 3–10 business days (including permits and purveyor approval).

  • Commercial/domestic containment: 1–3 weeks depending on plan check.

  • Fire systems: 2–4+ weeks due to dual reviews (fire + building).

• Budget considerations: Device cost (PVB to RPZ/Detector assemblies), enclosures or vaults, drainage work for RPZs, permit/plan check fees, and initial/annual testing.

To stay on schedule, our Backflow Testing Los Angeles experts recommend locking in shutoff windows with your purveyor early and scheduling testing the day of installation.

Work With Atlas Backflow Services

Atlas Backflow Services coordinates the entire process—device selection confirmation, purveyor approvals, permits, licensed installation (C‑36/C‑16 partners), and certified testing with digital reports accepted by local agencies.

Our Backflow Testing Los Angeles experts recommend letting us verify your purveyor’s current requirements so your project passes on the first inspection and stays compliant every year.Have questions about who is qualified to install your backflow prevention assembly—or need a fast quote?

Contact Atlas Backflow Services today. We’ll match your application to the right licensed installer, schedule your certified test, and handle the paperwork end to end.