How to start as a backflow tester in Colorado in 2026

Last updated 2026-08-19

Do you need a license to be a backflow tester in Colorado?

Colorado has no standalone statewide license called backflow tester. You need a tester certification a public water system will accept, then you apply to that system's approved tester list. If you install, repair, or relocate the assembly, that work is plumbing and needs a license from the Colorado State Plumbing Board.^[4]

That split trips people up. DORA's plumbing board licenses people who do plumbing. It does not hand out a tester card.^[5] Drinking water rules sit with CDPHE and with each public water system under Regulation 11 (5 CCR 1003-1).^[7]

So the real paper path is certification plus local acceptance. Not one state card.

Treat any search result selling a magic statewide backflow tester Colorado permit as noise. Ask who issues the credential. If the answer is ASSE, ABPA, or USC, that is a certification. If the answer is the State Plumbing Board, that is a plumbing license and it covers a different scope. For the license-shaped version of this same state, read backflow tester license in Colorado.

Can you test without any state occupational license? In plenty of Colorado towns, yes, if you hold a current recognized tester certification, your gauge is in cal, and the water system puts you on its list. Some cities are pickier. A few want testers to hold a plumbing license too. Read the utility's tester packet. Do not guess.

If someone pays you to cut pipe, replace an RP, or move an assembly, you have left testing and entered plumbing. Colorado regulates that work under Title 12, Article 155.^[5]

Short version. Certify, then get listed. License the plumbing only if you will touch the pipe.

What backflow tester certification does Colorado actually accept?

Most Colorado water systems accept a current personnel certification from a recognized body. The names you see over and over are ASSE 5110, ABPA tester certification, and the USC FCCCHR tester program.^[8][9]

No single CDPHE wallet card replaces those. CDPHE writes the drinking water rule. Each public water system decides which certs it will file tests from, and it publishes that choice in its cross-connection packet.^[7]

ASSE 5110 is the one Colorado schools advertise most. It is a written plus practical exam on reduced pressure assemblies, double checks, and the vacuum breaker family. Recertification is commonly every three years. Confirm the current cycle on ASSE's personnel certification page before you pay a school, because program rules are theirs, not mine.^[9]

USC's tester course has been a five day class for a long time. The training is excellent. It is also a plane ticket for most people on the Front Range. Take a local ASSE or ABPA class unless you already have a reason to sit at USC.^[8]

Online-only certificates with no practical exam are a bad bet. Utilities want proof you can hook up a differential pressure gauge and not wreck a relief valve. If a course cannot tell you where the wet lab is, skip it.

Pick the cert your first two target utilities already list. Add a second cert later only if a big account demands it. Stacking logos in month one wastes money.

Do you need a Colorado plumbing license to test backflow assemblies?

Often no, if all you do is test. Often yes, if you install, relocate, or repair. The State Plumbing Board licenses the trade of plumbing. Testing an assembly (test cocks, a gauge, a report) is not the same act as changing the device.^[4][5]

Colorado DORA's State Plumbing Board issues plumbing licenses and does not issue a separate backflow tester license.

That is the clean line on paper. The field is messier. A water utility can require testers on its list to hold a plumbing license. A building department can decide that pulling an assembly is plumbing. Your customer can ask you to "just swap this RP while you are here." That swap is the moment you need a plumbing license or a licensed plumber on the job.

Get the tester cert first. Work the test-only jobs. If you keep getting asked to repair, look at the residential or journeyman path on the Plumbing Board applications page and confirm current experience hours in 3 CCR 720-1. Those hour counts change by rulemaking. I will not invent them here.^[4][5]

Other states draw this line differently. Arizona's start path is a useful compare if you work the southern border towns. See how to start as a backflow tester in Arizona.

How much does it cost to start as a backflow tester in Colorado?

Nobody publishes a single official start-up number for a backflow tester in Colorado. The honest pile is a course, a cert fee, a test kit, annual calibration, insurance, and whatever your city charges to run a business. Confirm every dollar with the school, the certifying body, DORA, and the utility. Fees move.

The class is usually the cheap part. Colorado and regional schools have long advertised multi-day ASSE 5110 classes in a band from several hundred dollars to a bit over a thousand, exam sitting included or billed next to it. I will not lock a 2026 sticker price. Call two schools and compare what is actually in the seat fee.^[9]

The gauge is where people overspend. A new differential pressure kit from a known maker often lands in the high hundreds to around two thousand dollars, analog versus digital, new versus used. Utilities care that it is the right kind of kit and that it is in calibration. They do not care that it is this year's color. Buy used from a retiring tester if you can verify cal. A brand-new digital kit is nice. It is not required to get on a list.

Insurance is not optional if you want commercial accounts. General liability is the one property managers ask for. Some water systems want a certificate naming them. Shop it. I will not invent a premium.

Plumbing Board money only shows up if you also want to install. Application and exam amounts live on DORA's plumbing applications page. Read that page. Do not trust a blog for the current fee.^[4]

Business formation is separate. The Colorado Department of Revenue handles the sales tax license if you will sell taxable services or goods the way your city reads the rule.^[10] Confirm it before you file. A fancy shop build-out in month one is a waste. A calibrated kit, a cert card, and a way to file reports will get you paid.

How long does it take to become a backflow tester in Colorado?

The tester path is measured in days, not years. Most ASSE 5110 and similar classes run four or five consecutive days, with the written and practical exam at the end of that week.^[8][9] You then wait for the cert body to post the result and print the card. After that, each utility's approved-list process is its own clock. Some turn a complete packet in a few days. Some sit on it.

EPA's 2003 Cross-Connection Control Manual sets annual testing as the ordinary interval for backflow prevention assemblies.^[1]

That annual rhythm is why utilities bother listing testers at all. It is also why you should not vanish for eleven months after you get listed.

A Colorado plumbing license runs on a different clock. Experience, an exam, and board processing sit on DORA's side. Plan in years if you want to install, not in a long weekend.^[4][5] Confirm current experience rules in 3 CCR 720-1 rather than copying a number from a forum post.

Book the class only after you have read two utility tester packets and you know those systems will take the cert you are about to sit. Otherwise you can burn a week and still have nowhere to file a test. If you are comparing how long neighboring states take, backflow tester license in Arizona is the closest start-over guide on this site.

What does Regulation 11 require for backflow testing?

Regulation 11 is Colorado's Primary Drinking Water Regulations, filed as 5 CCR 1003-1. CDPHE and the Water Quality Control Commission use it to implement the federal Safe Drinking Water Act inside the state.^[3][7][11] The rule binds public water systems. It does not license you.

What you feel as a tester is the downstream program. The supplier has to run a cross-connection control program. Assemblies that protect the public system have to be tested. In practice that means tested when they go in, after they are repaired or moved, and at least once a year after that. EPA's older national manuals say the same thing in plainer English. EPA's Cross-Connection Control: A Best Practices Guide states, "Most states require that backflow preventers be tested by a certified tester at least annually."^[2]

The 2003 EPA Cross-Connection Control Manual puts the water system's job up front: "The purpose of this manual is to acquaint the water utility operator, water system manager, and local health official with the basic principles of backflow and backsiphonage and the accepted methods for providing protection to the potable water supply."^[1]

You are one of those accepted methods. You are not the regulator.

Read the current Regulation 11 text and CDPHE's cross-connection materials before you argue with a utility about due dates. I will not paraphrase a subsection number I cannot pin to today's filing. Open the rule. If a customer wants a waiver, that is the water system's call, not yours.

Federal Part 141 is the national drinking water floor. Colorado's rule is how that floor gets built here.^[3] California writes this differently, which is why how to start as a backflow tester in California is not a template you should copy onto a Denver route.

How do you get on a Colorado water utility tester list?

You apply to each public water system that owns the service connection. No statewide roster at CDPHE pushes your name to every town.^[7]

Denver Water is the example most Front Range testers hit first. It expects current certification plus whatever registration and reporting method it is using that year. Aurora, Colorado Springs Utilities, Fort Collins, and the special districts each have their own packet. Copy-paste one application onto another city and you will bounce.

A normal packet asks for a cert copy, photo ID, gauge make and serial, a current calibration certificate, and contact information. Some want insurance. Some want you to use their portal and no other. Some still take a paper form. Send what they asked for. Then call once.

Start with two or three systems you can actually drive. A tester listed in 40 towns and busy in none is just a filing hobby. Win repeat work on one campus or one property manager, then add the next district when a real assembly sits on the other side of the line.

Rural co-ops and tiny municipalities can be slower and more personal. The operator may know every RP in town. Be easy to reach in May. That is when annual tests stack up.

If a utility says it only accepts one cert body, believe it. Do not argue national reciprocity you cannot show in its written program.

What test kit and calibration do you need in year one?

You need a differential pressure test kit that the utilities on your list accept, plus a calibration certificate that is not expired. That is the whole equipment story for testing.

Most field kits are analog or digital three-valve or five-valve differential gauges made for RP, DC, PVB, and SVB procedures. Schools will tell you which layout they teach. Buy that layout so your muscle memory matches the sheet. Fancy extras (printers, Bluetooth, a second spare kit) can wait until you are actually double-booked.

Calibration is annual in the real world, because that is what utility packets ask for. Some labs turn a gauge in a week. Some take longer in the spring rush. Cal before the April pile, not during it. Keep the paper with the kit. A photo of a sticker is a weak backup if the sticker cooks off in a truck.

Do not test with a dead kit and promise to "send cal later." That is how you get dropped from a list.

Hand tools, fittings, and a way to capture the report matter more than a new truck. I would rather see a clean used van and a kit with fresh cal than a wrapped service body and an expired cert. The wrapped truck does not file the test.

Fire department connections and fire-line assemblies sometimes sit under a different contractor rule. If the device is on a fire suppression line, ask before you touch it. NICET or a fire suppression license can be in play. That is not the same paper as ASSE 5110.

How do you set up a backflow testing business in Colorado?

Treat it like any other small field trade. Form the entity if you want the liability wall, get the local business license the city actually issues, and ask Revenue whether your mix of testing needs a sales tax license.^[10] Confirm current filing amounts on the state sites. I will not quote a fee that may have moved.

If you hire anyone, Colorado workers' compensation rules kick in through CDLE. Read the Division of Workers' Compensation employer materials before you put a second person in the van.^[12]

You do not need a statewide general contractor license to exist. You may need plumbing contractor registration through the State Plumbing Board if you start contracting plumbing beyond testing.^[4] Local contractor licenses pop up in some municipalities. Ask the city that is printing your business license.

Banking, invoicing, and a way to store test reports for years are the unsexy core. Property managers will ask for last year's report in a hurry. Email folders named by address will save you. A $4,000 routing software subscription in month one will not.

Keep the first year ugly and cheap. Rent a corner of a shop. Print on the kitchen table. Spend on cal, insurance, and gasoline. The customers who want a polished brand already have a tester.

Compare this to states that wrap tester status into a single board card. Backflow tester license in California is that kind of different animal. Do not import it.

Testing versus installing: where new testers get burned

The fail is almost always the same. You show up to test. The RP dumps. The owner says fix it now. You have no plumbing license, no rebuild kit listed on the approval, and no permit if the city wants one. You either walk or you step into unlicensed plumbing.^[5]

Walk. Call a licensed plumber. Offer to retest after the repair. That retest is still your job.

The second fail is filing a test on a device you never saw, or pencil-whipping a pass. Utilities and building departments do talk. One bad report can cost the list that feeds you.

The third fail is working a town you are not listed in because "it's just one assembly." If that system later audits the report, you are the name on it.

Write a one-page scope you hand to every new account: test only, no repairs, no quotes to move an assembly, no fire-line work unless you hold that paper. Boring. It keeps you in business.

Alabama and other states mix these scopes their own way. If you are moving, read how to start as a backflow tester in Alabama instead of assuming Colorado rules travel.

What paper should you keep so utilities keep you on the list?

Keep a folder that can survive a request tomorrow morning. Current cert card. Gauge serial. Current calibration certificate. Insurance cert. Government ID. Each utility's approval email or login. Copies of the tests you already filed.

That is the first-year paper path. Not a national myth. Not a framed motto.

If you want that checklist in one kit, ASSEPath sells a $149 one-time ASSE 5110/5115 Tester Kit. A binder from the drugstore holds the same PDFs if you are organized.

Name files by site address and test date. When a district asks why last June is missing, you answer in one attachment.

Track recert dates on a calendar you actually look at. Three year cert cycles feel long until they are six weeks away and the only seat is on the Western Slope.^[9]

Keep the failed tests too. A fail plus a repair plus a retest is a clean story. A mysterious pass after a known dump is not.

Do not store this only on a phone. Phones die in toilets. A cloud folder plus a paper sleeve in the kit cover you when the portal is down and the inspector is not.

How do you stay certified after the first year?

Recertify before the card dies. ASSE 5110 and most peer programs run on a multi-year cycle, commonly three years, with a recert class and exam. Confirm the current rule with the body that issued your card.^[9] Do not wait for a utility to bounce a report and then tell you.

Cal the gauge every year, or sooner if you dropped it. Renew insurance before the certificate on file expires. Re-read each utility's tester rules when they mail an update, because portals change and old PDFs lie.

Stay reachable in the spring. Annual testing under Regulation 11 programs clusters when property managers wake up.^[2][7] Ignore calls in May and someone else gets the campus.

Do not buy more certs just to wallpaper the van. Add a cert when a real customer or a real utility writes it down as required.

No approval timeline is guaranteed. No board on this path promises you a seat next month. Confirm processing with the school, the cert body, DORA if you are also chasing a plumbing license, and the water system that has to accept your name.

ASSEPath publishes reference guides at /start. It is an independent publisher, not a law firm and not a service company. Use the boards for the final word.

Frequently asked questions

Do you need a license for backflow tester in Colorado?

No standalone statewide backflow tester license exists. You need a recognized tester certification (often ASSE 5110, ABPA, or USC) and a spot on each water system's approved list. Install or repair work is plumbing and needs a State Plumbing Board license. Confirm any local extra rule with the utility and DORA.

How much does backflow tester cost in Colorado?

There is no official statewide start-up price. Budget a multi-day course (often several hundred dollars to around a thousand), cert fees, a differential pressure kit (commonly the largest check), annual calibration, insurance, and local business filings. Confirm every current fee with the school, cert body, DORA, and your city. Do not trust old blog numbers.

How long does backflow tester take in Colorado?

A tester class is usually four to five days plus exam processing. Getting on a utility list can take days to a few weeks after a complete packet. A Colorado plumbing license, if you also want to install, is a years-long experience and exam path. Confirm current board timelines with DORA and each utility. Nobody can promise a date.

Does Colorado accept ASSE 5110 for testers?

Most public water systems in Colorado accept ASSE 5110 if the card is current and you complete that system's registration. Some also take ABPA or USC. Acceptance is the utility's call under its Regulation 11 program, not a single CDPHE tester roster. Read the packet for the towns you will actually drive.

Can I test backflow in Colorado if I am not a plumber?

Often yes for test-only work, if you are certified and listed. Installation, relocation, and repair are plumbing under Title 12, Article 155 and need a State Plumbing Board license. A few cities still want testers to hold a plumbing license too. Read the local utility rules before you quote a job.

How often do backflow assemblies need testing in Colorado?

Public water system programs built on Regulation 11 and on long-standing EPA guidance treat annual testing as the ordinary interval, plus testing after install, repair, or move. Your due date is the one on the water system's notice, not a guess. EPA's best-practices guide notes most states require certified annual tests.

Do I register with CDPHE as a backflow tester?

No. CDPHE writes Regulation 11 and oversees public water systems. It does not run a statewide tester license desk. You register with each public water system that will accept your reports. Keep CDPHE guidance bookmarked so you understand why the utility is asking for annual tests.

What gauge do I need to start testing in Colorado?

A differential pressure test kit that your target utilities accept, with a current calibration certificate. Schools teach a specific valve layout. Buy that layout. New digital kits are optional. A clean used analog kit with fresh cal will get you listed. Confirm accepted brands in the utility packet, not on social media.

How often should I calibrate a backflow test kit in Colorado?

Plan on at least annually, because that is what utility tester packets ask for. Cal sooner if you drop the kit or fail a check. Keep the lab certificate with the serial number. Expired cal is one of the faster ways to get pulled off an approved list in the spring rush.

Can one approval let me test anywhere in Colorado?

No. Each public water system keeps its own approved tester list. Denver Water acceptance does not put you on a mountain district's list. Apply where the assemblies actually are. Working a town you are not listed in is how reports get rejected later.

Do I need a contractor license to test backflow in Colorado?

Colorado has no single statewide general contractor license for tester-only work. You may need a local business license, a sales tax license if Revenue says your services are taxable, and plumbing contractor registration if you start contracting plumbing. Confirm with your city, the Department of Revenue, and DORA.

How do I recertify as a backflow tester in Colorado?

Recertify with the same kind of body that issued your card, usually on a three year cycle for ASSE 5110. Sit the recert class and exam before the expiration date. Then send the new card to every utility that lists you. Confirm the current recert rule on the certifier's page. Do not wait for a bounced report.

Sources

1. U.S. EPA, Cross-Connection Control Manual (EPA 816-R-03-002): Federal guidance manual on backflow principles, water-system programs, and accepted protection methods, including routine assembly testing.
2. U.S. EPA, Cross-Connection Control: A Best Practices Guide (EPA 816-F-06-035): EPA states that most states require backflow preventers to be tested by a certified tester at least annually.
3. eCFR, 40 CFR Part 141 National Primary Drinking Water Regulations: Federal national primary drinking water regulations that Colorado implements through Regulation 11.
4. Colorado DPO, State Plumbing Board applications and fees page: Colorado plumbing licenses and contractor applications are issued through the State Plumbing Board at DORA; current forms and fees are posted there.
5. Colorado DPO, Plumbing laws, rules, and policies: Plumbing practice in Colorado is regulated under C.R.S. Title 12, Article 155 and 3 CCR 720-1.
6. CDPHE, Drinking water regulations (Regulation 11 / 5 CCR 1003-1): Colorado Primary Drinking Water Regulations (Regulation 11) are the state drinking-water rules public water systems must follow, including cross-connection control programs.
7. USC FCCCHR, Tester certification program: The USC Foundation offers a recognized Backflow Prevention Assembly Tester certification course used by water systems nationwide.
8. Colorado Department of Revenue, Sales tax license: Colorado businesses that must collect sales tax apply for a sales tax license through the Department of Revenue.
9. U.S. EPA, Overview of the Safe Drinking Water Act: The Safe Drinking Water Act is the federal statute behind state drinking-water programs such as Colorado Regulation 11.
10. Colorado CDLE, Division of Workers' Compensation for employers: Colorado employers must follow Division of Workers' Compensation rules when they hire employees.