Last updated 2026-08-20
TL;DR
Radon mitigation lowers indoor radon, usually with active soil depressurization. A fan pulls soil gas from under the slab or a membrane and vents it above the roof. Start with a recognized mitigation course and exam, then check whether your state adds a license. EPA's action level is 4 pCi/L. There is no federal license. Confirm current forms and fees with the board before you bid.
What is radon mitigation?
Radon mitigation is the building work that lowers indoor radon gas, most often by pulling soil gas from under the house and venting it outdoors. The usual method is active soil depressurization. A fan and PVC pipe create a vacuum under the slab or a sealed membrane.
Radon is a radioactive gas from uranium in soil and rock. It moves into buildings through cracks, sumps, and hollow block. You cannot see it. You cannot smell it.
EPA estimates radon causes about 21,000 lung cancer deaths per year in the United States [1]. The National Cancer Institute lists radon as the second leading cause of lung cancer, after smoking [6]. CDC says the gas has no color, odor, or taste, which is why a test is the only way to know a building's level [15].
You are not scrubbing radon out of room air the way a filter grabs dust. You are changing pressure so soil gas does not keep entering living space. Some jobs add crack sealing, a crawl space membrane, or extra ventilation. Those help. The fan and the suction pit do the real work in most houses.
EPA's action level is 4 picocuries per liter (pCi/L). EPA also says you should consider fixing a home between 2 and 4 pCi/L [3]. WHO proposes a reference level of 100 Bq/m3, about 2.7 pCi/L [4]. Health Canada's guideline is 200 Bq/m3, about 5.4 pCi/L [5]. Those numbers are not the same. Clients will quote whichever one they googled.
"EPA recommends fixing your home if the results of one long-term test or the average of two short-term tests show radon levels of 4 pCi/L or higher." That sentence is from EPA's A Citizen's Guide to Radon [1]. Learn it. You will hear it on sales calls.
If you are entering the trade, mitigation means you design, install, and document a system that can be retested. It is construction plus a little radiation hygiene plus paperwork. Boards and buyers check the paper. The pipe is the easy part once you have done twenty slabs.
How do you start radon mitigation?
You start radon mitigation by learning the method, taking a recognized mitigation course and exam, then checking whether your state adds a license on top of national certification. There is no federal license. Do not bid paid work until you know your state's rule.
Here is the path I would actually walk.
Read the same EPA booklets your clients read so you use the same numbers they already saw [1][2]. Then take a mitigation course that NRPP or NRSB will accept. Kansas State University's National Radon Program Services is the long-running public training shop tied to EPA's radon program [15]. Pass the exam. Apply to NRPP or NRSB for the mitigation credential [11][12].
Call the state radon contact and ask one question. Does this state require its own license, registration, or certification to mitigate for pay? If yes, get that packet and fill it in slowly. If no, you still need a business registration, insurance, and, in many cities, a mechanical or electrical permit for the fan.
Buy the tools you will use on day one. A micromanometer. A U-tube or Magnehelic gauge. A drill and a core rig you can handle. PVC, fittings, a listed radon fan, and a system label. Learn ANSI/AARST SGM-SF, the soil gas mitigation standard for existing homes [13]. That document is what serious inspectors and many written specs point at.
Do not spend money on a van wrap or a franchise pitch before you have the credential and the state answer. That is a waste.
If you want a state walkthrough instead of a national slogan, use a real paper path like how to start radon mitigation in Colorado or how to start radon mitigation in Alabama. Those pages track board rules. They do not invent a coast-to-coast card.
Is there a federal radon mitigation license?
No. EPA does not issue a radon mitigation license to contractors. EPA sets guidance, funds state indoor radon work, and publishes the 4 pCi/L action level [3]. Certification is private. State licenses are state law.
People mix up three things. EPA guidance. An NRPP or NRSB card. A state license. Only the third can make paid work illegal if you skip it.
The 2005 Surgeon General advisory, which EPA still carries on its health-risk page, called indoor radon the second-leading cause of lung cancer in the United States [7]. That is a health warning. It is not a license and it does not deputize you.
HUD, VA, and some lenders ask for testing or mitigation on certain deals. Those are program rules. They still do not create a federal mitigator card you can hang on a van.
If someone sells you a national EPA license, walk away. Ask them to show the statute. They will not have one.
| Who | What they actually issue | What it means for you |
|---|---|---|
| EPA | Guidance and the 4 pCi/L action level | Not a license [3] |
| NRPP or NRSB | Private certification after a course and exam | Widely recognized, not a state card [11][12] |
| Some state health departments | A license or state certification | Can be required for paid work |
| City building department | A permit for the fan or wiring | Often required even when the state is silent |
Keep that table in your head when a trainer talks like one weekend unlocks fifty states. It does not.
What training and certification do boards actually accept?
NRPP and NRSB are the two national proficiency bodies most states and buyers recognize [11][12]. You take an approved course, sit for an exam, then apply. Measurement devices and quality assurance have their own tracks if you also test.
I would get the residential mitigation credential first. Add measurement if you will test your own work or sell testing. Some states forbid the same person from offering both on the same house. Ask before you print a combined flyer.
Course length for an entry mitigation class is often around two days, but confirm with the current provider catalog. I will not quote a school fee or an exam fee here. Those change. Confirm with NRPP, NRSB, and the school that will sit you.
Kansas State still runs the public-facing training lane many new people use [15]. Private schools exist too. Pick one the certifying body lists as approved. An unapproved weekend class is a waste of money if the exam board will not take it.
Recertification is periodic. Continuing education hours are real. Put the renewal date on a calendar the week you pass. Lapsed cards are how people lose a bid they already won.
If you want the paper checklist in one pile, RadonPath sells a $149 one-time NRPP Mitigation Kit. It is a document pack. It is not a license and it does not replace the board.
Which states make you get a separate radon license?
It depends. Some states wrote a statute. Some only keep a voluntary list. Some are silent and leave you with national certification plus local permits.
Illinois requires a Department license before you perform radon services for compensation under the Illinois Radon Industry Licensing Act, 420 ILCS 44 [8]. Florida's radon statute is section 404.056, Florida Statutes, and it is the hook for that state's radon program and professional rules [9]. Pennsylvania runs certification under 25 Pa. Code Chapter 240 [10]. Ohio licenses radon testers, mitigation specialists, and mitigation contractors under Ohio Administrative Code Chapter 3701-69 [14].
Other states lean on NRPP or NRSB and never issue their own card. California and Colorado are the kind of places people assume have one statewide mitigator license. Check the current board page anyway. Rules move.
I would treat every new state as a new file. Read the statute. Read the application. Call and ask what they want for proof of training, insurance, and exams. Then confirm fees with that board. Do not copy a blog fee table from 2019.
| State example | Paper you actually need | The document |
|---|---|---|
| Illinois | State license for paid radon work | 420 ILCS 44 [8] |
| Florida | Follow the radon statute and DOH rules | Fla. Stat. 404.056 [9] |
| Pennsylvania | State certification | 25 Pa. Code Ch. 240 [10] |
| Ohio | License tracks for specialists and contractors | OAC 3701-69 [14] |
| Many others | Often NRPP or NRSB only, plus local permits | Confirm with the board |
See radon mitigation license in California, radon mitigation license in Colorado, and radon mitigation license in Alabama for the paper, not a guess.
What does a real mitigation job look like on site?
A typical existing-home job is diagnostics, layout, install, and a post-mitigation test. That order matters. People who skip diagnostics buy extra fans later.
You walk the house. You find the slab, sump, crawl, or mix. You look for a communication path under the slab. You pick a suction point. You cut a pit, drop pipe, seal the slab penetration, run the stack, mount a listed radon fan, and discharge above the roof per the standard you are working to [13]. You label the system. You measure vacuum. You check leaks if the house needs it.
EPA told homeowners that most homes can be fixed for about the same cost as other common home repairs. The same 2016 consumer guide says the average cost for a contractor to lower radon levels in a home is about $1,200, although this can range from about $800 to about $2,500 [2]. That is 2016 EPA language. Labor and fan prices moved. Use it as a historical range, not your bid.
Post-mitigation testing is not optional if you want to claim the job worked. Follow the measurement protocol your state or the client named. Do not hand the owner a hardware-store charcoal kit and call it closed unless that is what the protocol and the contract allow.
A one-story slab with a good aggregate bed can go fast. A split level with a block wall and a wet crawl will not. Price the house in front of you.
How much does a first year in radon mitigation cost?
Nobody publishes a clean national startup budget I trust. The closest public cost figure is still EPA's 2016 homeowner range of about $800 to about $2,500 per installed system, with an average around $1,200 [2]. That is revenue context, not your overhead.
Your real first-year spend is training and exams, national certification, any state license, insurance, a vehicle you already have if possible, a core drill or a rental plan, fans and pipe stock, a micromanometer, and a website that does not lie. I would skip the wrap, the franchise, and the paid lead-gen contract in year one.
Confirm every government fee with the board that invoices it. I will not invent a current state fee or a processing time. Those change, and a wrong number is how people miss a filing.
Local permits can cost more than the state card. Ask the building department if a radon fan needs a mechanical or electrical permit. Many do. Some inspectors have never seen a radon stack. Bring a one-page spec.
Cash flow is lumpy. Winter test season is real in cold states. Build a reserve for fans and a second manometer before you hire anyone. A helper is cheaper than a ruined slab if you are still slow with a core rig. Hiring before you have work is how shops die in month four.
What standards and paper do you need on every job?
On paper, a complete job file has the pre-mitigation result, the contract, the system drawing or photo set, fan model and serial, suction readings, the label, and the post-mitigation result. AARST's SGM-SF is the standard most people mean when they say do it to code on an existing house [13].
Some jurisdictions adopted that standard or a close cousin. Some did not. Follow the stricter of the standard you advertised and the local rule. If your contract cites SGM-SF, you do not get to freelance the discharge location.
If you work multifamily or schools, different AARST standards apply. Do not use a single-family layout on a pod of apartments and hope. That is how you inherit a building.
Keep calibration certificates for any measurement device you own. Boards ask. So do picky listing agents.
Write the system label so a future tech can find the fan and the suction point without calling you. Include the install date and a service number. Owners sell houses. Your pipe stays.
Photograph the open pit, the sealed penetration, the fan nameplate, and the roof discharge. Those four photos settle more arguments than a paragraph in a proposal.
What should you ignore when people sell you a national myth?
The national myth is that one card lets you work everywhere tomorrow. It does not.
Another myth is that EPA licenses you. It does not [3]. EPA publishes guidance. States write licenses. Private bodies run exams.
A third is that a fan in the attic always knocks a 4 pCi/L house down. Communication under the slab can be poor. You may need extra suction points. You may need a crawl membrane. Diagnostics exist for a reason.
A fourth is that you should always seal every crack first and call that mitigation. Sealing helps. It is not the system. EPA's consumer guide puts the fan system at the center of home repairs [2].
A fifth is that a cheap general-purpose fan is fine. Use a fan listed for radon. Failed bearings and condensate in the wrong housing become callbacks, and callbacks eat first-year margin.
A sixth is that you can learn this only from social video. Watch video if you want. Then take the approved course, read SGM-SF, and do ride-alongs [13]. The exam is not hard if you have sat in a pit. It is hard if you have only watched a highlight reel.
How do you check your state board before you spend money?
Find the statute or the health department radon page. Download the application. Read the definition of mitigation and of work for compensation. Email the listed contact with your legal name and ask what credential they want to see. Save the reply.
Then confirm the fee, the bond if any, and whether they want a photo, a background check, or proof of insurance. I cannot give you a current fee. The board that cashes the check is the source.
If you plan to work across a state line, repeat the process. Reciprocity is uneven. Some boards waive a course if they like your NRPP file. Some make you sit again. Nobody has a single clean map I would bet a truck on.
How to start radon mitigation in Arizona and how to start radon mitigation in Connecticut are useful because they show how different the paper can look two states apart. Read those, then still call your own board.
If the person on the phone cannot answer, ask for the application instructions in writing. Verbal yes is not a file.
What happens after you install the system?
You commission the system. You record vacuum at the test port. You make sure the fan is running and the discharge is clear. Then you schedule a post-test, often after the fan has run long enough to meet the measurement protocol in force. You do not declare victory from a U-tube alone.
Tell the owner the fan must run all the time. Ice on an outdoor fan, a killed breaker, and a kid who unplugs the unit are the boring failures. EPA's citizen guide is still the booklet many owners get, and it is built around retesting, not a one-time ritual [1].
If the post-test is still high, you diagnose. More suction. Another pit. A membrane over bare soil. Do more than swap to a bigger fan and leave. A bigger fan on a tight soil bed just howls.
I would also tell the owner to retest every two years, and after a renovation that opens the shell. That advice matches how EPA talks to the public [1]. It also creates honest follow-up work without a hard sell.
Keep the job file for as long as your insurer and your state want. When a buyer’s inspector calls three years later, you will be glad you still have the pit photo.
Where should you go next for a state paper path?
Pick your state and read the license page before you buy tools. The work is straightforward on a lot of slabs. The paper is what trips people.
Start with the state you already live in. Then decide if a neighboring license is worth the second file. Crossing a line for one job is rarely worth a new bond.
Use the state guides when you want the forms and the sequence, not a pep talk. How to start radon mitigation in California is a different animal than a license-heavy Midwest shop. Read both kinds so you do not copy the wrong checklist.
RadonPath is an independent publisher, not a law firm and not a service company. If you want a starting packet, go to /start. Confirm every board fact yourself. No page on the internet, including this one, can promise an approval date.
Frequently asked questions
What is radon mitigation?
Radon mitigation is the work of lowering indoor radon, usually with active soil depressurization. A fan pulls soil gas from under a slab or membrane and vents it above the roof. Sealing and crawl membranes support the system. EPA uses 4 pCi/L as the action level. It is construction plus a retest, not an air filter.
How do you start radon mitigation?
Take an approved mitigation course, pass the NRPP or NRSB exam, then ask your state health department whether paid work also needs a state license. Add business registration, insurance, and any city permit for the fan. Do not bid until that file is clear. Confirm current fees with the board. There is no federal license.
What radon level requires mitigation?
EPA recommends fixing a home at 4 pCi/L or higher, and says you should consider action between 2 and 4 pCi/L. WHO proposes 100 Bq/m3, about 2.7 pCi/L. Health Canada uses 200 Bq/m3, about 5.4 pCi/L. Your contract and your state rule decide what you promise a client. The test protocol matters as much as the number.
Do I need a license to mitigate radon?
Sometimes. EPA does not license contractors. Some states, including Illinois, Pennsylvania, and Ohio, require their own license or certification for paid work. Other states accept NRPP or NRSB and stop there. Cities may still want a mechanical or electrical permit. Confirm with the state board before you take money.
Does EPA certify radon mitigators?
No. EPA publishes guidance, including the 4 pCi/L action level and consumer booklets. It does not issue a mitigator card. National certification runs through private bodies, mainly NRPP and NRSB. A state license, where it exists, comes from that state's statute or health department, not from EPA.
What is active soil depressurization?
Active soil depressurization is the common radon system. You open a suction pit in the slab or under a membrane, run PVC to a listed fan, and discharge outdoors above the roof. The fan keeps the soil side at a lower pressure than the house, so soil gas goes up the pipe instead of into rooms.
How much does a home radon system cost?
EPA's 2016 Consumer's Guide said the average contractor cost was about $1,200, with a published range of about $800 to about $2,500. That figure is old. Labor, fans, and permits moved. Use it as history. Bid the house in front of you, including extra pits, crawl membranes, and local permit fees.
Can I mitigate radon myself without a license?
Homeowners can often work on their own house. Paid work is different. If your state licenses mitigation for compensation, doing it for a neighbor for cash can be illegal. Even where the state is silent, a city may require a permit, and a buyer may reject an unlabeled system. Read the statute first.
What is NRPP certification?
NRPP is a national proficiency program. For mitigation, you take an approved course, pass an exam, and apply. Many states and buyers recognize it. It is not a state license. You still check the board in each state you work. Recertification and continuing education are part of keeping the card.
What is the difference between NRPP and a state license?
NRPP is a private certification after training and an exam. A state license is a legal permission created by statute or rule, such as Illinois 420 ILCS 44 or Ohio OAC 3701-69. Some states require both. Some require neither beyond local permits. Only the state board can tell you which pile you need.
Do I need a measurement certification too?
Get it if you will sell tests or run your own post-mitigation measurements for a claim. Some states split the two credentials and restrict the same person from testing and mitigating the same house. Ask before you print combined pricing. Keep device calibrations current if you own monitors.
How long does a mitigation install take?
A simple one-story slab can be a short day once you are competent. Mixed foundations, block walls, and wet crawls take longer. Diagnostics and the post-test add time after the pipe is up. Nobody has an honest national average I would print as a promise. Walk the house, then schedule.
How do I confirm fees with a state board?
Download the current application from the health department or licensing page. Call or email the listed radon contact and ask them to confirm the fee, any bond, and accepted payment. Save the reply with the date. Ignore old blog tables. Boards change fees. A wrong check delays the file.
Sources
- U.S. EPA, A Citizen's Guide to Radon (2016): EPA estimates about 21,000 U.S. lung cancer deaths per year from radon and recommends fixing homes at 4 pCi/L or higher.
- U.S. EPA, Consumer's Guide to Radon Reduction (2016): Average contractor cost to lower radon is about $1,200, with a published range of about $800 to about $2,500.
- U.S. EPA, What is EPA's action level for radon?: EPA's action level is 4 pCi/L and EPA says to consider fixing homes between 2 and 4 pCi/L.
- World Health Organization, Radon and health fact sheet: WHO proposes a reference level of 100 Bq/m3 and says a chosen level should not exceed 300 Bq/m3.
- National Cancer Institute, Radon and Cancer fact sheet: Radon is the second leading cause of lung cancer after smoking.
- U.S. EPA, Health Risk of Radon: Indoor radon is identified as the second-leading cause of lung cancer in the United States.
- Florida Statutes s. 404.056 (2023): Florida's radon protection statute is the legal hook for the state's radon program and professional rules.
- Pennsylvania Code, 25 Pa. Code Chapter 240 Radon Certification: Pennsylvania certifies radon service providers under Chapter 240.
- NRPP, Certification programs: NRPP is a national radon proficiency program that certifies measurement and mitigation professionals.
- NRSB, Certification: NRSB is a national radon proficiency body that certifies measurement and mitigation professionals.
- AARST, ANSI/AARST SGM-SF-2023 Soil Gas Mitigation Standards: SGM-SF is the ANSI/AARST soil gas mitigation standard for existing homes.
- Ohio Administrative Code Chapter 3701-69 Radon Licensing: Ohio licenses radon testers, mitigation specialists, and mitigation contractors under OAC 3701-69.
- CDC, About Radon: Radon is a gas you cannot see, smell, or taste, so testing is required to know indoor levels.