Last updated 2026-08-19
TL;DR
Colorado does not issue a statewide backflow tester license. You need a current tester certification from a body Regulation 11 accepts (ASSE, ABPA, or USC), then each public water system must take your reports. Repair or install work is plumbing. Confirm fees and lists with DORA and the utility. There is no state tester exam.
Do you need a license for backflow tester in Colorado?
No. Colorado does not hand you a statewide backflow tester license card. The state checks two things: whether you hold a current tester certification from an organization named in the Colorado Primary Drinking Water Regulations, and whether the public water system will accept your test report. Those are two separate gates, and both have to open before you get paid.
People search “backflow tester license in Colorado” because other states sell a single tester number. Colorado does not work that way. The Water Quality Control Commission wrote the drinking water rule. The State Plumbing Board writes the plumbing practice rule. Cities and special districts decide whose tests they will file. Nobody in Denver merged those desks.
If you only test assemblies and fill out the report, the drinking water rule is the one that names you. Regulation 11 talks about a Certified Cross-Connection Control Technician, not a DORA backflow license. [1] If you take the assembly apart, rebuild it, or replace it, that is plumbing work and the State Plumbing Board cares. [4]
Do not pay anyone who claims to “issue the Colorado backflow license.” It does not exist. Get the national tester credential, then call the water systems you actually want to bill. That is the real paper path.
The how-to companion for first-year operations sits next to this guide if you want the startup sequence after the credential question. how to start as a backflow tester in Colorado
What does Colorado Regulation 11 actually require for testers?
Regulation 11 requires public water systems to run a cross-connection control program and to have backflow prevention assemblies tested by a certified technician on a set schedule. The duty sits on the water system. You are the person they are allowed to use.
The Colorado Code of Regulations cites this as 5 CCR 1002-11, the Colorado Primary Drinking Water Regulations. [1] CDPHE’s cross-connection control program page is the working desk for that rule, not a tester licensing counter. [2] The Commission did not build a statewide tester roster you apply to.
Here is the line utilities keep reprinting from that rule: “Backflow prevention assemblies shall be tested by a Certified Cross-Connection Control Technician upon installation, repair, or relocation and at least annually from the last test date.” [1] Read that twice. Annual is the floor. Install, repair, and relocate each trigger a test even if the last sticker is only a month old.
The EPA’s Cross-Connection Control Manual still defines the hazard the rule is chasing. It says, “A cross-connection is any actual or potential connection between a public or a consumer's potable (i.e., drinking) water system and any source or system containing nonpotable water or other substances.” [3] Colorado’s tester language exists because of that connection, not because the state wanted a new occupational board.
Your report has to be usable by the supplier. If the city cannot file it, you did not test for them, even if your national card is valid. That is why local approval is not optional busywork.
Is a Colorado plumbing license required to test backflow assemblies?
Not for a test-only visit, in most towns. Repair, rebuild, or replacement is a different job, and that job sits under the State Plumbing Board. Confirm the line with DORA before you open a device, because the board, not the water department, owns plumbing scope. [4]
Title 12, Article 155 of the Colorado Revised Statutes is the plumbing practice act. It requires a board license before a person works as a residential, journeyman, or master plumber. [5] The board’s rules live in 3 CCR 720-1. [4] Testing a device and writing a pass/fail report is not the same act as cutting pipe or swapping a relief valve.
Plenty of utilities will take a test from a certified technician who is not a licensed plumber. The same utilities will reject you the minute you offer to “fix it today.” Keep those hats on separate invoices until you hold the plumber card.
Journeyman applicants have long needed four years of practical experience in the trade under Article 155. Residential is a shorter experience path. Masters sit on top of journeyman. Confirm current hours, apprenticeships, and exam vendors on the board applications page, because substitutions change and I will not invent a processing clock. [9]
If your plan is test-and-repair across the Front Range, budget the plumbing license as the long pole. The tester class is the short pole.
Which backflow tester certifications does Colorado accept?
Colorado points water systems at nationally recognized tester credentials. In practice that means ASSE, ABPA, or the USC Foundation for Cross-Connection Control and Hydraulic Research. Regulation 11 is the document that names the certified technician. It does not sell the class. [1]
ASSE’s backflow prevention assembly tester credential is the one most Front Range schools put on the flyer. ASSE publishes that path as its 5110 tester qualification. USC still runs its own tester certification out of the Foundation. [11] ABPA runs a tester certification that Colorado utilities also see on applications.
Pick the card the water systems on your route already know how to file. Call two or three purveyors before you pay a school. If Denver Water, a special district, and a mountain town all say ASSE, do not get cute with a rare certificate and spend winter arguing with a clerk.
Online theory with no wet lab is a bad bet. Testers fail in the field on hose setup and on reading a differential pressure gauge, not on vocabulary. Take a class with assemblies on a stand and water in the pipes.
Keep the wallet card and the expiration date. Utilities will ask. CDPHE will not mail you a replacement state seal, because they never issued one.
How much does backflow tester cost in Colorado?
There is no state backflow tester license fee, because there is no state backflow tester license. Your real spend is the national class, the gauge, calibration, insurance if you contract, business filings if you invoice under a company name, and whatever each utility charges to sit on its tester list. Confirm every dollar with the school, DORA, the Secretary of State, and the water system. I will not invent a current board fee.
Schools set their own tuition. Front Range ASSE 5110 classes are private products. Prices move with the lab, the exam sitting, and whether a retake is included. Treat any number you see on a Facebook ad as stale until the school emails you a current invoice.
The differential pressure gauge is the tool that actually costs real money. Cheap no-name kits fail calibration and then your tests get thrown out. Buy a serviceable analog gauge from a vendor that can still certify it, and skip the fancy digital unit until you have a route. Gauge certification is usually annual. Denver Water asks testers for current certification paperwork when they register. [6]
If you form an LLC or file a trade name, that is a Secretary of State filing, not a tester license. [12] If you sell taxable goods or meet the Department of Revenue’s sales tax rules, you file there separately. [8] Plumbing license fees, if you go that road, are on DORA’s current materials. Read the current schedule. Do not use a blog number from 2019.
First-year people waste cash on truck wraps, extra certifications they will not use, and “state application” packets sold by people who do not work in Colorado. Spend on the class, a gauge that will pass certification, and liability insurance if you are walking onto commercial sites.
Paper checklists help some people keep the forms straight. ASSEPath sells a $149 one-time ASSE 5110/5115 Tester Kit if you want that pile in one place. It is not a Colorado license and it will not put you on a utility list.
How long does backflow tester take in Colorado?
The tester class itself is usually a single work week plus the exam sitting at the end of that week. You are not waiting on a state tester board, because that board does not exist. The slow steps are utility registration and, if you want to repair, the plumbing experience clock.
ASSE tester certification is built as a multi-day course with a written exam and a hands-on exam. USC’s tester program is the same shape: class time, then a practical. [11] I have no honest statewide average for “days until your first paid test,” because each supplier runs its own intake. Some cities take a PDF and a card photo and you are on the list that week. Some want a gauge cert, a W-9, and a portal login, and they move when they move. Confirm with the utility. No one can promise you a date.
Already hold a current ASSE, ABPA, or USC tester card from another state? The class clock may already be done. You still have to clear each Colorado water system. Do not assume reciprocity. Colorado is not granting you a state number. It is asking whether your national card is current.
The plumbing license, if you need it, is measured in years of documented experience plus exams. Article 155’s journeyman path is the four-year experience gate unless the board accepts a listed substitution. [5] That is a career decision, not a weekend add-on.
Plan the tester week this month. Plan utility calls the week after you pass. Plan plumbing only if you intend to turn wrenches on failed assemblies.
How do you get on a Colorado water system approved tester list?
You apply to the water system, not to CDPHE, as an individual tester. Each supplier keeps the list that makes their Regulation 11 file defensible. CDPHE checks the system. The system checks you. [2]
Denver Water publishes contractor backflow instructions and expects testers to hold current certification and to file through its process. [6] Colorado Springs Utilities runs its own cross-connection desk and its own tester expectations. Special districts and mountain towns often use a one-page registration and an email inbox. Ask for the current form. Do not reuse a 2018 PDF you found in a search result.
Bring the same pile every time: photo ID, tester certification with expiration, gauge model and serial number, current gauge certification, and contact information that matches the name on the report. If you work under a company, bring the SOS record so the name on the invoice matches something real. [12]
Start with two or three systems you can actually drive weekly. A statewide spray of registrations feels busy and produces no tests. Water systems care that you show up in their service area and that your reports are readable.
If a clerk says they only accept one certifying body, believe the clerk. Regulation 11 sets the floor. Local procedures can be tighter. Arguing the regulation in the lobby does not get your portal login issued.
What paper should a backflow tester in Colorado carry on day one?
Carry the national tester credential, a photo ID, the current gauge certification, blank forms or portal access for the test report the utility wants, and proof of who you are invoicing as. That is the field kit. The rest can stay in the truck box.
Utilities reject reports for dumb reasons. Wrong assembly serial number. Gauge cert expired last Tuesday. Tester name does not match the card. Company name on the form does not match the SOS record. Fix those before you leave the driveway. [6]
If you are a plumber as well, carry the DORA license in the same folder. Site supers will ask. They will not care that Regulation 11 does not require it for a test-only visit. [4]
Keep a copy of the last calibration certificate in the gauge case, not “somewhere in email.” Field techs lose arguments when the paper is at home.
You do not need a CDPHE tester permit in that folder. If someone told you to print one, they were describing another state.
How often do you recertify as a backflow tester in Colorado?
Your national tester card expires on that body’s cycle, commonly three years for ASSE, and the water system will drop you when the card dies. Colorado does not send a recert letter, because Colorado did not issue the card.
ASSE recertification is its own process: course or exam path, then a new expiration date. USC and ABPA run their own clocks. Do not mix them up. If your Denver file says ASSE, renew ASSE. [6]
Gauge certification is a separate clock and it is usually annual. A fresh tester card with a stale gauge still produces a rejected report in a lot of Colorado towns.
Renew the gauge first, then the tester card, then email the utilities that already have you on a list. Waiting until the week you expire is how you lose April, which is when commercial assemblies actually get scheduled.
Confirm the current recert method with the body that issued your card. Schools change vendors. I will not invent a sitting fee.
What do Denver, Colorado Springs, and other big utilities want?
They want a current national tester credential, a gauge they can trace, and reports in their format. They do not want a story about a statewide license. Read the current contractor page for each one before you drive. [6]
Denver Water’s backflow contractor materials are the model a lot of smaller systems copy. If you can satisfy Denver’s file, you can usually assemble the same packet for a district. [6] Colorado Springs Utilities keeps cross-connection information on its own site and will not honor a Denver login.
Aurora, Fort Collins, Thornton, and the special districts each have a person who actually opens the PDFs. Find that person. A general customer-service line will bounce you.
Big systems fail testers for portal mistakes more than for field technique. Use the form they named. If they want a specific test report layout, stop using the one your school printed in 2016.
Do not build a business that only works if one metro utility likes you. Hold at least two lists so a portal outage does not zero your week.
Can you test in Colorado with an out-of-state backflow certification?
Yes, if the credential is current and it is one the water system accepts under Regulation 11, usually ASSE, ABPA, or USC. You still register locally. The other state’s card number is not a Colorado license and it does not move with you automatically. [1]
Arizona and California testers run into this every spring. Those states have heavier state-shaped programs. Colorado will look at the national mark on your card, then ignore the out-of-state agency number. Compare the paper before you assume the same folder works. backflow tester license in Arizona backflow tester license in California
If your only credential is a state-issued tester number with no ASSE, ABPA, or USC mark, expect to sit a class. Call the target utility first so you do not pay for a course they will not file.
Alaska and Arkansas testers asking the same question hit the same wall: national card plus local list, not a compact. backflow tester license in Alaska how to start as a backflow tester in Arkansas
What equipment does a Colorado backflow tester actually need?
You need a differential pressure gauge the utility will accept, fittings for the assemblies you will see, a way to record the test the supplier wants, and personal gear for mechanical rooms and outdoor pits. You do not need a van full of rebuild kits unless you are also the plumber.
The gauge is the whole business. If it fails certification, your week fails with it. Get it certified on a published schedule and keep the paper with the tool. Denver’s tester intake is explicit about certification records. [6]
Skip the electronic gauge in month one. They are easy to love in a classroom and expensive when they go in for service. A known analog unit that a local lab will still certify is enough.
Hoses, adapters, and a simple site kit matter more than branding. RP, DC, and PVB assemblies in Colorado mechanical rooms are not exotic. Your school should have put your hands on those three.
Leave the rebuild parts in the shop until DORA would agree you are allowed to install them. [4]
What is a waste of money in your first year as a tester?
Paying for a fake Colorado tester license is a waste. So is a second national certification you will not register, a wrapped truck before you have a route, and a $3,000 gauge you cannot get certified in Pueblo on a Friday.
Another waste is treating CDPHE like a licensing board. They wrote a drinking water rule for suppliers. They did not open a tester window. Emailing them for a card number just burns a week. [2]
Skip the “nationwide reciprocity” packages too. Colorado water systems do not honor a binder. They honor a current card and their own form. [1]
Spend the first year on one good class, one good gauge, two or three utility lists, and clean reports. Add the plumbing license only if failed assemblies are how you want to earn. Add a company filing when a customer asks for an invoice that is not your personal name. [12]
Want a paper checklist for the 5110/5115 path? The kit on /start is the same $149 one-time pile mentioned above. Use it or ignore it. The utilities will not ask which publisher you read.
Frequently asked questions
Do you need a license for backflow tester in Colorado?
No statewide tester license exists. You need a current ASSE, ABPA, or USC tester certification that Regulation 11 recognizes, and each public water system must accept your reports. Repair or install work needs a Colorado plumbing license from DORA. Confirm both desks before you advertise.
How much does backflow tester cost in Colorado?
There is no state tester fee. Budget a private national tester course (schools set tuition), a differential pressure gauge, annual gauge certification, insurance if you contract, SOS and tax filings if you invoice as a firm, and any utility registration cost they publish. Confirm current DORA plumbing fees only if you will repair assemblies.
How long does backflow tester take in Colorado?
The tester class is typically one week plus the exam sitting. Utility registration can be days or longer. Confirm with each supplier. A plumbing license, if you need one to repair, follows years of documented experience plus board exams. Nobody can promise an approval date.
Does Colorado accept ASSE 5110 for backflow testers?
Yes. ASSE’s backflow prevention assembly tester credential is the card most Colorado schools and utilities already know how to file. Regulation 11 points suppliers at certified technicians from recognized national bodies. Still ask the water system you will bill, because local intake can be pickier than the rule.
Can I test backflow assemblies in Colorado without a plumbing license?
Often yes for test-only work, if you hold an accepted tester certification and the water system lists you. Opening, rebuilding, or replacing an assembly is plumbing practice under Title 12, Article 155. Confirm scope with the State Plumbing Board before you turn a wrench on a failed device.
Do I register with CDPHE as a backflow tester?
No. CDPHE oversees public water systems and Regulation 11. It does not issue individual tester cards. You register with each supplier that will file your reports. If a school told you to apply to CDPHE for a tester number, they described the wrong agency.
How often do Colorado backflow testers recertify?
On the cycle of the body that issued your card. ASSE tester certification is commonly a three-year cycle. Gauge certification is usually annual and utilities treat it as a separate document. Renew both before they expire or your reports stop counting.
Can I use an Arizona or California tester card in Colorado?
You can use the national mark on that card if it is current ASSE, ABPA, or USC and the Colorado utility accepts it. The other state’s agency number does not transfer. Register locally. If your only credential is a state number with no national mark, plan on a class.
Is there a Colorado state exam for backflow testers?
No. There is no DORA or CDPHE backflow tester exam. You sit the written and hands-on exams your certifying body requires, usually at the end of the tester course. Plumbing exams are separate and only apply if you pursue a plumber license.
Do I need a contractor license to invoice backflow tests?
Testing is not a statewide contractor class of its own. If you form an entity, file with the Secretary of State. Sales tax accounts sit with the Department of Revenue when their rules apply. Local business licenses are city or county paper. Confirm each one. Do not treat any of them as a tester license.
Will an online-only backflow tester course work in Colorado?
I would not rely on it. Utilities and certifying bodies care about a hands-on exam on real assemblies. A video week with no wet lab is how people fail the practical or get questioned when they cannot set up a gauge. Take a class with water in the pipes.
Who has to test backflow assemblies in Colorado each year?
A Certified Cross-Connection Control Technician. Regulation 11 requires assemblies to be tested on installation, repair, or relocation, and at least annually from the last test date. The public water system has to make that program work. You are the technician they are allowed to use.
Do I need insurance to test backflow in Colorado?
The drinking water rule does not sell you a tester insurance product. Site owners and utilities often ask for general liability before they let you on the property. If you have employees, workers’ compensation is a CDLE question. Confirm what the property and the water system want in writing.
What if I only want to test for one Colorado city?
Then you only need the national card plus that city’s tester file. Skip the statewide myth and the extra registrations. Get their current form, their report layout, and their gauge rules. One clean list beats ten neglected ones. Add a second system when you actually have drive time.
Sources
- Colorado Secretary of State, 5 CCR 1002-11 Colorado Primary Drinking Water Regulations: Regulation 11 requires backflow assemblies to be tested by a Certified Cross-Connection Control Technician upon installation, repair, or relocation and at least annually.
- CDPHE Water Quality, Cross-Connection Control program: CDPHE administers cross-connection control for public water systems under Regulation 11 and does not operate as an individual tester licensing board.
- U.S. EPA, Cross-Connection Control Manual (EPA 816-R-03-002): EPA defines a cross-connection as any actual or potential connection between a potable water system and a source of nonpotable water or other substances.
- Colorado DORA State Plumbing Board, Laws, Rules, and Policies: The State Plumbing Board publishes the practice act and 3 CCR 720-1 rules that govern who may perform plumbing work, including assembly repair and replacement.
- Colorado General Assembly, Colorado Revised Statutes 2023 Title 12 (Article 155 Plumbers): Title 12, Article 155 requires a board license to work as a residential, journeyman, or master plumber and sets the journeyman experience gate at four years of practical experience.
- Colorado Department of Revenue, Sales tax license: Businesses that meet Colorado sales tax rules must obtain a sales tax license from the Department of Revenue, which is separate from any tester credential.
- Colorado DORA State Plumbing Board, Applications: Current plumber license applications, experience documentation rules, and exam steps are posted by the State Plumbing Board and must be confirmed there.
- USC Foundation for Cross-Connection Control and Hydraulic Research, Tester certification: USC FCCCHR operates a nationally recognized backflow tester certification program that Colorado utilities accept as a qualifying credential.
- Colorado Secretary of State, Business filing forms: Trade names and entities used on tester invoices are filed with the Colorado Secretary of State and are not a substitute for tester certification.