Radon mitigation invoices: the photo shows a pipe, the follow-up test shows the level

A test in a ground-floor unit comes back high, a mitigation company installs a system, and the invoice comes with photos: a white pipe running up the outside wall, a fan, a gauge on the basement wall. The photos may be perfectly real. But radon is a gas you can’t see, so no photo of a pipe shows the level came down. The record that does is a radon test, run after the system has been working. This piece covers what the photos can show, what they can’t, and what to ask for before you pay. It follows the EPA’s Consumer’s Guide to Radon Reduction (2025 revision), which is written for homes, not apartment buildings. It is not legal advice.

Why the photo can’t answer the question

EPA’s guide says to fix a home “if your radon level is confirmed to be 4 picocuries per liter, pCi/L, or higher.” The whole point of the job is that number. A pipe on the wall shows a system is there. It doesn’t show the system was designed for that building, that the fan is running, or that the air in the unit now tests lower. Only a measurement shows that.

What the photos can show

• That a system was installed somewhere, and roughly how: where the pipe runs, where the fan sits, where it vents.
• The parts EPA says to look for. Its checklist for “checking your contractor’s work” says “Radon reduction systems must be clearly labeled” and “A warning device must be installed to alert you if an active system stops working properly.” A label and a gauge are both things a photo can show.
• Where it vents. The same checklist says exhaust pipes of soil suction systems “must vent above the surface of the roof and 10 feet or more above the ground”, with distance rules for nearby windows and doors. A wide photo of the outside of the building can show whether that looks right. It can’t measure it.
• Sometimes when. If the file still carries the camera’s own clock, it should fall on the day of the job.

What they can’t

• The radon level. Not before, not after.
• That the fan is on. A gauge photographed once shows one moment. EPA’s guide says the fan “must run continuously for the system to work correctly.”
• Which building. One white pipe on a stucco wall looks a lot like another, and a company with many jobs has many photos of them.

The record that answers it: the post-mitigation test

EPA’s guide is specific about this test:

• When. “A post-mitigation radon test should be done within 30 days of system installation, but no sooner than 24 hours after your system is in operation with the fan on, if it has one.”
• How long. “To test the system’s effectiveness, a two- to seven-day measurement is recommended.” Windows and doors “must be closed 12 hours before and during the test, except for normal entry and exit.”
• Who. The contractor may test its own work, but the guide says “it is recommend that you also get an independent follow-up radon measurement. Having an independent tester perform the test, or conducting the measurement yourself, will eliminate any potential conflict of interest.”

That last point is the one that matters for an invoice. A test the contractor ran and reported is still the contractor’s own record. A test you or someone else ran is not.

Checks before you pay

1. Ask for the test that started the job. The result, the dates it ran, and which unit it was in. The job should be in the unit or building that tested high.
2. Ask for the post-mitigation result, with the dates the test ran. Compare them with the install date on the invoice. A test that started less than 24 hours after the fan went on, or that ran for less than two days, is short of what EPA’s guide recommends. That is a question to ask, not a finding.
3. Get your own follow-up measurement, as EPA recommends, by an independent tester or with a kit yourself. It is the one number in the file that doesn’t come from the company sending the bill.
4. Ask who did the work and what credential they hold. EPA says many states require radon professionals “to be licensed, certified or registered”, and points to your state radon office and two national programs, the National Radon Proficiency Program (NRPP) and the National Radon Safety Board (NRSB). The guide notes that private programs “usually provide members with a photo ID card, which indicates their qualifications and the ID card’s expiration date.”
5. Ask for a photo of the label and the gauge, and look at the gauge yourself on your next visit. The guide says to look at the warning device, “usually a manometer, on a regular basis to make sure the system is working correctly.”
6. Ask for the original photo files, not pictures pasted into an invoice PDF, which have usually lost their camera record. Why, and how to ask for the originals.
7. Drop this job’s photos in with the company’s earlier ones. The checker marks any two files in the same batch that are the same file, even under different names. A pipe photo reused from another building shows up that way, if it is the same file. A new photo of a different building won’t, which is why the test result matters more than the picture.

After it’s paid

EPA’s guide says “It is a good idea to retest your home at least every two years to be sure radon levels remain low,” and that fans “may last for five years or more” before needing repair or replacement. A later invoice for a replacement fan raises the same question as the first one: the photo shows a fan, and a test shows whether the level stayed down.

Whether someone used AI on the photos

A picture of a pipe on an exterior wall is easy to generate now, and some generators write a mark into the file saying so. The checker reads those marks in photos, and the notes some phone editors leave when generative AI was used to alter a photo. A file with no such mark is not proven real. Most fakes and most genuine photos look the same to a file reader once they have been through a chat app or a screenshot. And a genuine photo of a radon system still says nothing about the radon level.

The limits, stated plainly

• We read the EPA’s Consumer’s Guide to Radon Reduction (EPA 402/K-10/005, marked 2025) and its page on finding a radon professional (updated December 30, 2025), in November 2026. The guide is written for homes. We did not read the industry standards for apartment buildings.
• We did not check any state’s radon law, including any rules on what landlords must tell tenants or when they must mitigate. Check with your state radon office.
• A low post-mitigation result shows the level during that test. It doesn’t show the price was fair or that every line on the invoice was done.
• Our example is made up. We don’t know how often radon invoices are padded or follow-up tests are skipped.
• A photo with no camera record is not a fake. Text messages, chat apps and many portals remove the record from genuine photos every day.
• Our checker gives no confidence score and does not judge a picture by looking at it. It reads what is in the file, in your browser, and uploads nothing. A file with no AI marker is not proven real.
• This is not legal advice.

Related: furnace replacement invoices and the permit record, and water mitigation invoices and the drying log.

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