A backflow testing business is a side path plumbers can take — the testing credential is the gate, and the rules that drive the work come from the local water purveyor or code authority that requires the tests.
What we won't hand you is an earnings figure: BLS's OEWS wage series excludes self-employed workers, so it doesn't say what an independent tester makes.
This guide covers what our research confirms — startup costs, rates, purveyor lists, insurance and paperwork — and where it stops.
Is backflow testing a good side business?
The case for it rests on the shape of the work — where local programs keep backflow prevention assemblies on a testing cycle.
Whether that cycle recurs, and when it comes due, are your water purveyor's or code authority's to set: annual testing is a common local rule our research could not confirm from a primary source, so treat their notice as the authority on both.
Where a cycle does run, the work is route work: a set of assemblies you return to when the program's cycle comes due.
That shape is what makes testing schedulable around a full-time job.
The gate is a credential, and it has a real bar.
ASSE 5110 — one option among tester certifications, since many jurisdictions run their own — requires at least five years of documented related field experience, a 40-hour training course, a written exam and a hands-on practical on four assembly types: reduced pressure principle (RP), double check (DC), pressure vacuum breaker (PVB) and spill-resistant vacuum breaker (SVB).
Sometimes the entry sits beside the plumbing licence: Louisiana's Water Supply Protection Specialist endorsement is available to licensed journeyman or master plumbers — or licensed landscape irrigators — who complete a 40-hour tester certification; the State Plumbing Board accepts ASSE or ABPA tester certifications, renewed every three years.
The field is established: ASSE counts more than 19,000 ASSE-certified backflow professionals working across every U.S. state and parts of Canada, trained at 100-plus ASSE-approved schools.
Established cuts both ways — those 19,000-plus are already working across every U.S. state and parts of Canada — which is why this page spends its space on where a new route actually comes from (the purveyor programs below) rather than demand talk.
Two scope decisions shape the business early.
First, testing and repair are separate disciplines in ASSE's series — the 5110 tester and the 5130 repairer — so a testing-only business can stop at the test and hand failed assemblies to a repair-certified colleague.
Second, know where testing rights stop: in Texas, a licensed Backflow Prevention Assembly Tester (BPAT) may work on fire lines only if permanently employed by an Approved Fireline Contractor, so a side business there stays off fire-line assemblies unless that employment tie exists.
And the money honesty, up front: BLS's OEWS wage series excludes self-employed workers, so it has no row for you as an independent.
The benchmark this page can publish is the employed plumbers' figure, and it is exactly that — a payroll number, not a price list.
New to the credential itself?
Our backflow tester career guide covers the role, who hires testers and the pay data that does exist.
Startup costs
The honest headline: our research verified no course prices, no kit prices and no per-test fees, so this page publishes no cost total — a guessed figure would be worse than none.
What it can do is map where the confirmed costs sit, so you can get a real quote for each before you commit.
The credential side is where the confirmed numbers live, and Texas's BPAT route itemizes the requirements.
Its TCEQ BPAT licence — required of anyone who tests or repairs backflow prevention assemblies in Texas — asks for a high school diploma or GED, two years of approved experience (the state counts master or journeyman plumbing work, water system operation, irrigation and fire sprinklers among them) and a TCEQ-approved 40-hour BPAT course; one of those two years can be substituted with 32 semester hours of college credit or 20 extra training hours.
The application fee is $111 — the only licence fee this page's research confirmed, set by TCEQ, not a national figure.
The written exam runs at a TCEQ-approved computer-based testing centre, and the practical is given by the training provider.
Renewals are a recurring line item, not a one-time hit.
Texas BPAT licences are valid three years and need 24 hours of continuing education to renew, 8 of them hands-on practical training.
On the ASSE side, certifications renew every three years, and 5110 recertification means at least an 8-hour class plus a written exam — 50 questions today, rising to 100 from January 1, 2027 — and a practical exam.
State schedules differ: Arkansas credentials Assembly Testing Technicians on a two-year cycle and lists no state fee in our research, which is a prompt to check your own board's current fee schedule, not a promise of free.
Equipment is the other bucket, and it is the one our research could not price: we verified no kit figures at all, so treat any number you see as unverified until your purveyor and training provider confirm it.
Our backflow test kit guide covers what a differential kit does, calibration rules and what can and cannot be confirmed on cost, and the class side is its own decision — our guide to the backflow certification class covers course hours and where to enroll.
No cost total here — on purpose
What to charge
Straight answer: we have no verified per-test rate to print.
Rates are local: they depend on the programs you work under, the reporting each one requires and what testers near you already charge — and our research confirmed no figure for any of those.
A "typical" price invented for this page would misprice your first quote, so there is no rate table here.
The pay data that does exist measures employees, not businesses.
In May 2025, BLS's OEWS put the median wage for plumbers, pipefitters and steamfitters (SOC 47-2152) at $30.67 an hour, or $63,800 a year — wage-and-salary workers only, and OEWS excludes the self-employed, so it says nothing about an independent tester's revenue.
Use it as the benchmark for what your hours earn on someone else's payroll; your own billing has to cover those same hours plus the kit, the licence renewals, continuing education and the admin time the reports take.
The state-level tables live on our backflow tester salary page.
When you do set numbers, price the visit rather than the minutes on the gauge: the trip, the setup, the form and the follow-up ride along with the job.
And keep your credential calendar inside the math — ASSE recertification every three years and, in Texas, 24 CE hours per three-year renewal are real costs that a one-test price has to carry across the whole route.
Getting on purveyor lists
The program is the authority: the local water purveyor — your water utility — or the code authority that requires the tests.
Annual testing is a common local rule our research could not confirm from a primary source, which is exactly why the first call goes to them, not to this page: ask which credential they accept, which field-test procedure they expect, and how they want results filed.
The procedure question is real — some jurisdictions require a specific one, and ASSE's list includes the USC 10th Edition, ASSE, EPA, Illinois, Missouri, one-hose and TREEO procedures.
One of them has a published manual behind it: the USC Foundation for Cross-Connection Control and Hydraulic Research publishes the Tenth Edition Manual and runs a tester course that pairs lectures with hands-on wet-lab exercises.
The credential they accept varies by jurisdiction, and states issue their own in several places.
Texas requires its TCEQ BPAT licence for anyone who tests or repairs backflow prevention assemblies.
Minnesota's backflow (RPZ) tester and rebuilder credentials require current ASSE 5110 or 5130 certification.
Louisiana adds the Water Supply Protection Specialist endorsement to a licensed journeyman or master plumber's licence (or to a licensed landscape irrigator's credential) — the 40-hour certification, with ASSE or ABPA accepted.
Virginia certifies backflow prevention device workers on 4 years of water-distribution experience plus 32 hours of board-approved training, or 7+ years plus 16 hours, with ASSE testing standards and a wet lab required.
Washington's Backflow PL30 plumber specialty certificate requires a DOH Backflow Assembly Tester certificate, and Wisconsin issues a Cross Connection Control Assembly Tester credential among its restricted plumber credentials.
Some programs keep the list themselves.
North Dakota's plumbing board lists certified backflow assembly testers, and in Missouri, St. Louis County's plumbing licensing office — part of its Department of Transportation and Public Works — issues backflow (BFD) tester certificates of its own, a reminder that the authority can be a county rather than the state.
Our backflow tester license-by-state guide maps the board-by-board detail; the practical move for a new route is calling the purveyors in your service area and asking what they require from a new tester.
Credentials and testing rules are jurisdiction by jurisdiction
Insurance and paperwork
The business runs on two calendars.
The first belongs to the assemblies: each program defines its own paperwork and cycle — annual testing is a common local rule our research could not confirm from a primary source, so your purveyor's notice is the authority on when the work recurs and when it comes due.
The second calendar is your own credential's.
Texas BPAT licences are valid three years and need 24 CE hours to renew, 8 of them hands-on; ASSE certifications renew every three years through at least an 8-hour class, the written exam (50 questions, rising to 100 from January 1, 2027) and a practical; Louisiana's Water Supply Protection Specialist endorsement renews every three years; Arkansas's Assembly Testing Technician credential runs on a two-year cycle.
Our research did not cover what a lapse costs you — grace periods, late renewal, re-exams are the issuing body's rules, not ours — so ask them before the date; either way, the renewal dates belong in the books.
Insurance is the part we can't source, so we won't act like we can: our research did not cover tester insurance requirements, and we verified no rule saying who must carry what.
Whoever sets a requirement — a state board, a water program, or the contractors and property owners who hire you — will say so directly: ask each program you sign up with what proof it needs, and take coverage questions to a licensed insurance agent in your state before your first job.
The same honesty applies to business registration and taxes.
Whether you need an LLC, a local business licence or a separate tax registration is outside this research — confirm with your state's business-registration agency and a tax professional.
None of that changes the structure underneath: the credential is the gate, and the work runs on the programs' cycles.
Career information, not legal or financial advice — testing requirements, cycles and credentials are set by your water purveyor, state program or licensing board; insurance, business registration and tax questions need a licensed professional in your state. Confirm the current rules with each authority before you act on them.