There is no single backflow certification every state accepts — the credential that counts is the one your state program or water purveyor names.
ASSE 5110 is the ASSE Series 5000 standard for backflow prevention assembly testers; ABPA tester certifications count where a board accepts them; and USC's Foundation for Cross-Connection Control and Hydraulic Research publishes the manual behind the field-test procedure and trains testers.
Here is how the three compare, and who accepts which.
What ASSE 5110 is
ASSE 5110 is the professional-qualification standard for a Backflow Prevention Assembly Tester in ASSE's Series 5000 line — the series that also covers cross-connection surveyors (5120), assembly repairers (5130), a fire protection system standard (5140) and backflow prevention program administrators (5150).
A tester holding it is examined over the testable backflow prevention assemblies that protect a building's drinking supply, and the practical exam covers the four assembly types the work involves: RP, DC, PVB and SVB.
The entry route ASSE sets puts documented experience first: at least five years of related field experience, a 40-hour training course, then a written exam and a hands-on practical exam.
That five-year rule is ASSE's own, not a universal one — it binds candidates seeking the ASSE certification, not the field.
ASSE counts more than 19,000 certified backflow professionals across the U.S. and parts of Canada, trained at more than 100 ASSE-approved schools.
Holding the standard is a maintenance commitment too.
ASSE certifications renew every three years, and recertifying up to six months early loses no time on the cycle; 5110 recertification requires at least an 8-hour class, a 50-question written exam — rising to 100 questions from January 1, 2027 — and a hands-on practical exam.
That describes the credential itself.
Whether a given jurisdiction accepts it is a separate question, and the one this page answers below.
The how-to side — eligibility paperwork, choosing a course, sitting the exams — is covered in our backflow tester certification guide, and the role and pay picture in our backflow tester career and pay guide.
ABPA, AWWA and USC programs
When a water purveyor or state program lists the credentials it accepts, three names come up beside ASSE's: ABPA, AWWA and the USC Foundation for Cross-Connection Control and Hydraulic Research (FCCCHR).
What our research could confirm about each differs — and the gaps matter as much as the facts.
The USC foundation sits on the procedure side of the field.
It publishes the Tenth Edition of its manual and runs a Tester Training Course that combines lectures with hands-on wet-lab exercises.
The manual's procedure is also one of the field-test procedures ASSE-certified testers can be examined on: ASSE tests to several procedures — USC 10th Edition, ASSE, EPA, Illinois, Missouri, one-hose and TREEO — and some jurisdictions require a specific one.
What the verified record does not show is the USC foundation certifying testers, so if a posting or purveyor mentions a "USC certification," confirm with the program asking for the test exactly what it means.
ABPA tester certifications are accepted by name in at least one state program: Louisiana's State Plumbing Board states it "currently accepts all testing certifications issued by ASSE or ABPA" for its Water Supply Protection Specialist endorsement.
Beyond the boards that name ABPA in their rules, our research did not confirm the details of ABPA's tester program — who can sit it, or where else it is accepted — so the accepting program is the authority there too.
AWWA also comes up in searches about backflow certification.
Our research did not verify an AWWA tester certification program — nothing about its content, its exams or where it is accepted — so we will not describe one.
If a purveyor, board or job posting names an AWWA credential, ask the program that requires the test which certifications it accepts before you pay for any course.
The pattern across all three: the credential that counts is whichever one the program requiring the test names.
That decision, not the certifying body's reputation, is what to nail down first.
State and purveyor acceptance
Acceptance is decided by whoever requires the test — the state program or the water purveyor.
The confirmed map below runs from standalone state licences through plumber-licence endorsements to credentials that name ASSE directly, plus one board that accepts more than one body's certification.
| Jurisdiction | Credential | What the rule says |
|---|---|---|
| Texas | TCEQ Backflow Prevention Assembly Tester (BPAT) licence | Required of anyone who tests or repairs backflow prevention assemblies. Entry: high school diploma or GED, two years of approved experience, a TCEQ-approved 40-hour course. |
| Arkansas | Assembly Testing Technician / Assembly Repair Technician | State-issued pair: the testing credential runs two years, the repair credential is lifetime; no state fee listed. |
| Virginia | Backflow prevention device worker | Four years of water-distribution experience plus 32 hours of board-approved training, or seven-plus years plus 16 hours; ASSE testing standards apply and training must include a wet lab. |
| Wisconsin | Cross Connection Control Assembly Tester | State-issued credential listed among Wisconsin's restricted plumber credentials. |
| Minnesota | Backflow (RPZ) tester/rebuilder | Requires current ASSE 5110/5130 certification. |
| Louisiana | Water Supply Protection Specialist endorsement | For licensed journeyman or master plumbers (or licensed landscape irrigators) who complete a 40-hour tester certification; ASSE or ABPA certifications accepted. |
| Washington | Backflow PL30 specialty plumber certificate | Rides on the plumber licence and requires a Department of Health Backflow Assembly Tester certificate. |
| Maryland | Journey Plumber/Gas Fitter licence | Backflow rides on the plumber licence: 32 hours of backflow prevention device testing training among the requirements. |
| North Dakota | Certified tester list | The State Plumbing Board lists certified backflow assembly testers. |
| St. Louis County, Missouri | Backflow (BFD) tester certificate | Issued by the county's plumbing licensing office alongside its plumber licences. |
Three patterns matter.
First, a state licence can displace the question entirely: Texas requires its BPAT licence of anyone who tests or repairs backflow prevention assemblies, and our research did not confirm whether an ASSE 5110 certification substitutes for any TCEQ requirement — ask TCEQ before assuming it does.
Second, states can write ASSE into their own rules: Minnesota's backflow (RPZ) tester credential requires current ASSE 5110 certification, and Virginia applies ASSE testing standards to its backflow prevention device worker training.
Third, acceptance can be multi-body: Louisiana's plumbing board accepts ASSE and ABPA certifications alike.
Renewal runs on separate clocks from acceptance.
ASSE certifications renew every three years; Texas BPAT licences are also valid three years but need 24 hours of continuing education — 8 of them hands-on practical training — to renew.
And the calendar that matters locally may be neither: state programs and water utilities set their own renewal cycles for testers, often annual or biennial.
Confirm the calendar with the program that registers you.
Which certification counts is decided locally — verify before you enroll
ASSE 5120 and 5130
ASSE's Series 5000 is bigger than the tester standard.
The professional-qualification line covers 5110 Backflow Prevention Assembly Tester, 5120 Cross-Connection Control Surveyor/Specialist, 5130 Backflow Prevention Assembly Repairer, 5140 Fire Protection System and 5150 Backflow Prevention Program Administrator.
Testing is the assembly-level field credential in that line-up; the surveyor standard sits over cross-connection survey work, and the repairer standard over repairing the assemblies testers evaluate.
The clearest confirmed acceptance point for the repairer standard is Minnesota: the state's backflow (RPZ) tester and rebuilder credentials require current ASSE 5110/5130 certification.
Beyond that, our research confirmed the standards' names and coverage but not their entry routes or exam formats — we did not verify how a candidate qualifies for 5120 or 5130, so treat ASSE and its approved schools as the source for those specifics.
If your path runs toward surveying systems or administering a cross-connection program rather than field-testing, those are the standards to ask about — and the renewal cycle is ASSE-wide: every three years.
Once the right credential is in hand, backflow tester jobs on HVACHires are where it goes to work.
Career information, not legal advice — certification and licensing requirements are set by state programs, licensing boards and local water purveyors. Confirm the current rules with the authority in your jurisdiction before you act on them.