USC cross-connection control resources, and how they relate to your work

The Foundation for Cross-Connection Control and Hydraulic Research at the University of Southern California is a university-based research and education organisation that has worked on cross-connection control for decades. Its influence on day-to-day testing comes from three activities: laboratory evaluation of backflow prevention assemblies, publication of the Manual of Cross-Connection Control with its field test procedures, and tester and specialist training.

It is not a regulator. It does not issue you a licence, it does not receive your test reports, and it does not approve software. What it produces is technical material that regulators, state programs and water purveyors may adopt, reference or amend when they write the rules you actually work under.

When a requirement is unclear, work down this chain rather than assuming the most familiar source wins. The specific authority nearly always governs.

1. 1

   Federal framework

   The Safe Drinking Water Act and EPA regulations set the national floor and delegate primacy to states. Nothing at this level tells you what differential to record.

2. 2

   State program

   State drinking water or plumbing rules set certification requirements, testing frequency, report retention and often the accepted procedure and form. This is where 'annual' becomes a legal obligation.

3. 3

   Water purveyor / local program

   Your purveyor administers the program: which assemblies it approves, which form it accepts, how and where you submit, deadlines, and what happens on a failure. Local amendments live here.

4. 4

   Referenced technical material

   USC Foundation, AWWA and ASSE material, as adopted or referenced by the levels above — the procedure and the assembly criteria in practice.

5. 5

   Manufacturer instructions

   Assembly-specific service, repair and parts requirements. Programs commonly require repairs to follow them, and they can be stricter than the general procedure.

What this means for the report you hand in

There is no single national backflow test form, and no software can honestly claim its PDF is accepted everywhere. A complete, legible report carrying the facility, assembly identity, measured readings, failures with reasons, repairs, retest, tester credential, gauge calibration and signatures satisfies most reviewers — but where a purveyor mandates its own form, that form is what you file. Confirm before the visit, not after.

• Cross-connection — any actual or potential connection between potable water and a source of contamination. The connection is the hazard; backflow is the event that exploits it.
• Backsiphonage — reverse flow caused by negative or reduced supply pressure, such as a main break or heavy demand. Vacuum breakers address this case only.
• Backpressure — reverse flow caused by downstream pressure exceeding supply pressure: booster pumps, elevated tanks, boilers, injectors. Vacuum breakers do not protect against it.
• Degree of hazard — whether a cross-connection threatens health (contaminant) or only quality and aesthetics (pollutant). This drives which assembly is required, which is why hazard classification belongs on the report.
• Containment versus isolation — protection at the service connection to protect the public main, versus protection at the individual fixture or process inside the premises. Many programs require both.
• Air gap — a physical vertical separation. It is the most reliable protection and needs no annual test, but it cannot be used under continuous pressure.

The practical translation of the hierarchy above into the order you do things:

1. 1

   Read the notice before you drive out

   It usually names the purveyor, the deadline, the assembly on file and sometimes the required form. Mismatches between the notice and the assembly in the vault are worth catching before you start.

2. 2

   Confirm the assembly matches the hazard and the application

   A vacuum breaker on a service with backpressure, or a double check on a health-hazard service, is a reportable condition regardless of how the readings come out.

3. 3

   Follow the adopted procedure and record what you measure

   Take readings in the sequence your program adopts, and write the numbers down as measured. Missing readings are incomplete, not passes.

4. 4

   Repair and retest as one record

   Keep the failed initial readings, record what was repaired, then take a full second reading set. A passing retest is reported as passed after repair.

5. 5

   File on the accepted form, on time

   Submit as the purveyor requires and keep your copy for the retention period your state sets. Set the next due date while the record is still in front of you.

BackflowPass covers the middle of that list: open the generator to capture the facility and assembly, grade readings live, record repairs and retest, sign on the screen and export one 8.5×11 page — offline, no account needed. For the thresholds themselves see the pass/fail calculator, and for per-assembly field detail the RPZ, DCVA and PVB references.

Go to the source for anything that affects a filed report. Editions change, and a summary — including this page — is not a substitute.

• USC Foundation for Cross-Connection Control and Hydraulic Research — the manual, approved-assembly information, field test procedures and training.
• American Water Works Association — cross-connection control practice guidance used widely by utilities.
• ASSE International — assembly product standards and professional qualification standards for testers.
• US EPA drinking water regulatory information — federal requirements and state primacy.
• IAPMO and your adopted plumbing code — installation requirements including clearance, height and drainage.
• Your state drinking water program and your water purveyor's cross-connection control office — the only authorities on your form, your deadline and your accepted procedure.