Backflow tester requirements change at the state line.
Texas requires its own TCEQ BPAT licence of anyone who tests or repairs backflow prevention assemblies.
Louisiana's tester endorsement rides on the plumber licence, landscape irrigators included; Washington's backflow plumber specialty takes a Department of Health (DOH) tester certificate; Maryland builds backflow training into its journey plumber licence; and Arkansas, Virginia, Minnesota and Wisconsin issue state tester credentials of their own.
Where no state licence surfaced in this research, a water supplier or local program may be the registering authority.
States where backflow sits inside the plumber-licence system
Start with the states where backflow plugs into the plumber licence — as an endorsement, a specialty, or training the licence itself requires.
Louisiana's Water Supply Protection Specialist endorsement is available to journeyman or master plumbers licensed through the State Plumbing Board of Louisiana — or to landscape irrigators licensed through the Department of Agriculture and Forestry — who complete a 40-hour tester certification.
The board states it currently accepts testing certifications issued by ASSE or ABPA, renewed every three years.
Washington's version sits on the plumber licence too: its Backflow PL30 specialty plumber certificate requires a DOH Backflow Assembly Tester certificate.
Maryland folds backflow training into the licence ladder itself — a Journey Plumber/Gas Fitter must have held an apprentice licence at least 4 years, completed 7,500 hours under a licensed master plumber, completed 32 hours of backflow prevention device testing training, and passed a written exam.
Candidates upload proof of hours, backflow certification and ID to PSI, which administers the Maryland State Board of Plumbing exams.
Texas runs both models.
Beside the standalone TCEQ licence covered below, TSBPE offers a Water Supply Protection Specialist endorsement for Journeyman, Master or Inspector licences — one of its three endorsement types, alongside Medical Gas Piping Installation and Multipurpose Residential Fire Protection Sprinkler Specialist — and a plumber holding it may perform customer service inspection certifications for public drinking water systems under 30 Tex.
Admin.
Code Chapter 290.
Our research did not confirm that the endorsement replaces the BPAT — the BPAT requirement covers anyone who tests or repairs backflow prevention assemblies.
Louisiana's endorsement hangs on a 40-hour tester certification — what that course covers, what it costs and how the exams run is the job of our backflow tester certification guide.
States that issue their own tester licence (Texas BPAT and its peers)
Texas is the clearest standalone case.
A person who repairs or tests the installation or operation of backflow prevention assemblies must hold a licence issued by TCEQ: the Backflow Prevention Assembly Tester (BPAT).
The licence comes with a scope edge built in — BPATs may work on fire lines only if permanently employed by an Approved Fireline Contractor.
Entry runs through TCEQ's own checklist: a high school diploma or GED, two years of approved experience — the agency's examples include master or journeyman plumbing work, water system operation, irrigation and fire sprinklers — and a TCEQ-approved 40-hour BPAT course.
One of those two experience years can be substituted with 32 semester hours or 20 extra training hours.
The application fee is $111; the written exam is taken at a TCEQ-approved computer-based testing centre, and the practical is given by the training provider.
The licence is valid three years and renews on 24 hours of continuing education, 8 of them hands-on practical training.
Arkansas, Virginia, Minnesota and Wisconsin each issue tester credentials of their own.
Arkansas certifies Assembly Testing Technicians on a two-year credential, with a lifetime Assembly Repair Technician credential beside it and no state fee listed.
Virginia certifies backflow prevention device workers through the Board for Contractors (DPOR), which licenses backflow tradesmen statewide: four years of water-distribution experience plus 32 hours of board-approved training, or seven-plus years plus 16 hours — with ASSE testing standards applying and a wet lab required in the training.
Minnesota's backflow (RPZ) tester and rebuilder credentials require current ASSE 5110/5130 certification.
Wisconsin issues a Cross Connection Control Assembly Tester credential among its restricted plumber credentials.
Where no state licence surfaced: board lists, county programs and water suppliers
Outside the state-credential list the picture thins, and honest limits matter more than tidy categories.
What the cross-state research confirmed beyond the state-credential states above is two narrower arrangements.
North Dakota's plumbing board keeps a list of certified backflow assembly testers — a state registry.
And the research confirmed one Missouri arrangement, in one county: the St. Louis County Department of Transportation and Public Works plumbing licensing office issues backflow (BFD) tester certificates alongside its journeyman and master plumber licences.
Two states sit just outside the confirmed set.
In North Carolina, our research found no separate backflow-tester licence on the plumbing board's qualification list — what is confirmed is a Restricted Limited Plumbing contractor licence covering exterior backflow preventers on piping 2 inches or less.
The gap in our notes is not proof the state has no tester rule; ask the board.
Iowa appears to run a separate backflow prevention assembly tester registration program — the administrative-rules reference (481 IAC chapter 476, formerly 641 IAC 26) showed up in a rules transfer table we read — but we did not confirm the program's details, so treat the state as the authority there.
Florida is a state this research did not cover — and that is the honest shape of the wider gap: beyond the rows above, this page cannot tell you who registers testers.
The research's own open questions flag the pattern to expect in unlisted states: backflow rules there are often water-purveyor programs, run by the utility that owns the pipes rather than a licensing board.
That pattern is not verified state by state, and even the local rules are hard to pin down: "annual" testing and annual test-gauge calibration, for example, are common local rules our research could not verify from a primary source — attribute them to the local water purveyor or code.
Before testing in any state without a confirmed state credential, ask your water supplier and your state plumbing board who registers testers.
The map is only as current as the research — verify before you apply
Backflow tester requirements, state by state
The table pulls what the research found into one view — a testing licence here, a licence requirement, a registry or a local certificate there.
Only the state itself can say which gate applies to you.
Every row traces to a state source; the two rows we could not verify say so.
| State | Credential our research found | The rule in brief |
|---|---|---|
| Texas | TCEQ BPAT licence | Required of anyone who tests or repairs backflow prevention assemblies. Entry: diploma/GED, two years of approved experience, a TCEQ-approved 40-hour course; $111 application fee. Fire-line work only while permanently employed by an Approved Fireline Contractor. |
| Louisiana | Water Supply Protection Specialist endorsement | For licensed journeyman or master plumbers (or licensed landscape irrigators) with a 40-hour tester certification; ASSE or ABPA certifications accepted, renewed every three years. |
| Arkansas | Assembly Testing Technician | State credential valid two years; a lifetime Assembly Repair Technician credential sits beside it; no state fee listed. |
| Virginia | Backflow prevention device worker | Board for Contractors (DPOR): four years of water-distribution experience plus 32 hours of board-approved training, or seven-plus years plus 16 hours; ASSE standards; wet lab required. |
| Minnesota | Backflow (RPZ) tester / rebuilder | Requires current ASSE 5110/5130 certification. |
| Washington | Backflow PL30 specialty plumber certificate | The specialty requires a DOH Backflow Assembly Tester certificate. |
| Wisconsin | Cross Connection Control Assembly Tester | State credential listed among Wisconsin's restricted plumber credentials. |
| Maryland | Journey Plumber/Gas Fitter licence | Includes 32 hours of backflow prevention device testing training among its requirements; proof of backflow certification is uploaded with exam paperwork to PSI. |
| North Dakota | Board tester list | The state plumbing board lists certified backflow assembly testers. |
| Iowa | Tester registration program (unconfirmed) | A separate registration program appears in the administrative rules (481 IAC chapter 476, formerly 641 IAC 26); details not confirmed — check with the state. |
| North Carolina | No separate tester licence confirmed | A Restricted Limited Plumbing contractor licence covers exterior backflow preventers on piping 2 inches or less; tester rules unconfirmed — check with the board. |
| St. Louis County, Missouri | Backflow (BFD) tester certificate | Issued by the county's Department of Transportation and Public Works plumbing licensing office. |
Absence from this table is not a rule.
For the states where we could not confirm a credential, the registering body may be your water supplier or a local program — the research's open questions flag backflow rules in unlisted states as often water-purveyor programs, unverified state by state.
Ask the utility and the state plumbing board before you test anything.
The board-by-board map is the licensing half of the role.
What the work pays, who hires testers and how the side business builds is our backflow tester career and pay guide, and backflow tester jobs on HVACHires show who is hiring now.
Career information, not legal advice — backflow tester licensing is set by state boards, state environmental agencies and local water purveyors. Confirm the current requirements with the authority that would register you before you act on them.