"Buying a Home in Maine: Who Can Run My Radon Tests, and Why Are There Two?"

Once a Maine home is for sale, a tester registered with the state has to run the radon test. The exemption that lets an owner test their own home stops applying once the home goes on the market, and it never applied to you as the buyer. If the home is on a private well, you are booking two separate tests, because air and water get measured separately.

I'm Jeff Moran, a mortgage broker in Bluffton, South Carolina, originating since 1996, licensed in fifteen states, including Maine, NMLS #483943, through C2 Financial Corporation. I write about the state rules that move money and time on a purchase, and this is one of the ones that quietly eats a Maine inspection window.

I am not going to tell you what radon does to a person or what number is too high. That belongs to the state health people and to the tester you hire. What I can tell you is who Maine allows to do the work, how many appointments you are actually booking, and where the cost of acting on the results lands in a purchase you are closing on a deadline.

Who is allowed to run a radon test on a Maine house that is for sale?

Maine runs a registration system for this, which most states do not, and it is in the statute itself rather than in a trade association's rules.

Under the Radon Registration Act, 22 M.R.S. chapter 165, section 774 says a person may not perform, evaluate, or advertise to perform or evaluate tests for the presence of radon in buildings or on building lots unless that person is registered with the division. The requirement reaches providers whose place of business is outside Maine and who offer radon testing to people in Maine, so a company an hour over the New Hampshire line is not outside the rule.

Section 775 puts the same requirement on the fix. A person may not offer advice or plans to reduce the level of radon in a structure, or contract to modify an existing structure in a way meant to reduce radon, unless registered. Testing and reducing are two registrations doing two jobs.

Then there is the carve-out, and it is the part worth reading twice. Section 776 exempts a person performing testing or mitigation on a building owned or inhabited by that person, but not for sale at the time that person does the work.

Two consequences come out of that one clause, and both of them are about you.

The first is that the seller cannot hand you a result they produced themselves during the listing. A homeowner who tested their own home three years ago while they lived there was covered. The same homeowner testing it the week your offer gets accepted is not, because the home is for sale.

The second is that you were never covered at all. The exemption is written around a person who owns or lives in the building, and you are the buyer. So the hardware-store kit you were thinking of buying does not put a usable result in your file. It may be perfectly accurate, and it is still not something you can ask a seller to act on.

Why does a home on a private well need two radon tests?

Because they measure two different things, and one result tells you very little about the other.

The Maine CDC's radon guidance draws the line plainly. An air test measures what is in the air inside the home and does not tell you by what path the radon got there. A water test is the one recommended for a home on a drilled well, and it measures only what is in the water. Radon can come up through the soil under the home, and it can also come out of the water at the taps and the shower. An air number that looks fine does not rule out the water, and a water number does not stand in for the air.

The two problems also get fixed in two different places, which is where the money separates. An air system is construction: a pipe and a fan on the home, drawing soil gas from under the slab and venting it above the roofline. A water system is equipment plumbed into the line before the water reaches your taps, either aeration or a granular activated carbon unit the water passes through. Maine CDC publishes its own guidance on those carbon units, including what happens to the carbon later. Two different trades, two different quotes.

So when your inspector says "I can do a radon test," the useful next question is which one, and whether they hold the registration for it. On a home connected to a public water system, the air test is the whole conversation.

What has the seller already had to tell you?

Some of this arrives before you spend anything, and it is worth reading closely rather than initialling.

33 M.R.S. § 173 requires the seller of residential property to give you a property disclosure statement, and it names what has to be in it. Radon is one of the hazardous-materials items, alongside asbestos and underground oil storage tanks. The statute goes further than a yes-or-no box: if the water or the air has been tested for radon in the two years before the transaction, the seller discloses those results to you.

The private water supply gets its own item in the same statute. Where the property has one, the seller discloses the type of system, where it is, any malfunctions, the date of the most recent water test if there was one, and whether they have had a problem such as an unsatisfactory result or a result with notations.

Read those two items together and you have most of what you need to plan the week. A disclosed test from eighteen months ago means a registered tester has already been on the property and you have a number to start from. A blank means nothing was tested in that window, which is not the same as nothing being there. And the water-supply item tells you whether you are on a well at all, which decides whether this is one appointment or two.

The disclosure covers what the seller knows. It is not a warranty and not a substitute for your own testing, which is why the inspection window exists.

How do you get both tests booked inside the inspection window?

The order matters more than the speed, because an air test needs the home closed up for a set period and you cannot compress that by paying more.

1. Read the property disclosure the day you get it, looking for the radon items and the private water supply item. That is what tells you whether you are arranging one test or two.
2. Confirm the water source before you book anything. The listing language is the usual tell. If it says well, drilled well, or private water, plan on the water test.
3. Check registration before you hire. The provider your inspector recommends may hold the air registration and not do water sampling at all, and those are commonly two different companies. Ask whether they are registered with Maine for the specific test you are ordering.
4. Get the air test started early in the window. It runs for a period with the home kept closed up, and the clock on that period is the part people underestimate.
5. Order the water sample in the same conversation if the home has a well, and ask each provider for the turnaround on results rather than only the appointment date. The lab time behind a water sample is what decides whether you still have room to negotiate.
6. If a result comes back and you want work done, get the quote inside the window. A registered mitigation provider under section 775 is a different hire from the tester, and a quote in hand is what lets you ask the seller for something specific instead of something vague.

Does my lender require any of this?

No, and knowing that is what puts the decision back in your hands.

Radon testing is not one of the property questions a standard purchase loan asks. What a loan does ask about a home on a private system is whether the water is safe and continuously available and whether there is a safe method of sewage disposal, and that is a different test with its own rules about who may draw the sample. What a loan actually checks on a well and septic covers that ground, and a radon result does not answer it or replace it.

Radon testing lives inside your inspection contingency instead, so the choice and the money are yours. Where it touches the file is in the cash and in the timing.

If the seller agrees to pay for the work, that money reaches you as a credit at closing or as work completed before closing, and those two do different things to what you bring to the table. How a seller credit moves your cash to close walks through that choice. If the work gets done instead, it is a repair rather than a lender condition, and what an appraiser looks at compared with what an inspector looks at is the distinction to keep straight if somebody asks whether the appraisal has to be revisited.

The timing side is where a purchase actually slips. Your inspection contingency has a date on it, and so does your rate lock, and so does your closing. A result that arrives three days late and starts a negotiation running another week puts pressure on all three.

What usually goes wrong?

Treating the inspection as one package somebody else is managing. The home inspector is running their own inspection. Radon may or may not be part of what they are registered and equipped to do, and water sampling frequently is not. Nobody is assembling the list on your behalf.

Assuming an air result covers the well. The air came back fine, so the home is fine, and the water was never sampled. It is the most common version of this on a Maine purchase and it comes from good intentions.

Buying a kit, which costs less and produces nothing you can use in a transaction, for the reason in section 776 above.

Booking the air test late, which is how a buyer ends up choosing between waiving a contingency and asking for an extension the seller has no reason to grant.

Reading a blank disclosure as a clean result. No test in the last two years means exactly that.

An illustration, so the order is clear

Numbers and dates below are made up to show the sequence. They are not a quote, not a real file, and not what anything costs.

You go under contract on a Tuesday on a home outside Brunswick with a drilled well, and you have a ten-day inspection window. The disclosure comes over Wednesday morning. The radon item is blank, and the private water supply item names a drilled well with a water test date from four years ago and no notations. Blank plus a well means two tests and no head start.

Wednesday afternoon you call the inspector. She is registered for air testing, does not do water sampling, and gives you a name for the water side. You book her air test to start Thursday and the water sample for the same Thursday access visit, so nobody makes two trips. The home stays closed up for the test period, and the water lab quotes results back in several business days.

By Monday of week two you have both results with three days left. If something needs work, there is time to get a quote from a registered mitigation provider and put a specific number in front of the seller. If both come back clean, you release the contingency having spent the window on information instead of on waiting.

Run the same file with the air test booked on day eight and the results land after the contingency expired. Every option you had on Monday is gone.

Where to start

Get the financing settled before the inspection window is the thing consuming your attention. Run your numbers with no credit pull, no account, and nobody calling you, and you will see pricing for your own scenario rather than a national average. When you want the letter behind the offer, what a Maine pre-approval involves covers it, and the Maine closing rules that decide who pays what is the wider picture on what a purchase here costs. No letter from anyone is a loan commitment; final approval depends on the property, the appraisal and full underwriting.

If you are looking in more than one state, Illinois answers this same subject through two required disclosure documents rather than a registration scheme. The answer changes at every state line.

Common questions

Can I do my own radon test on a house I am buying in Maine?

Not in a way the state's scheme recognises. Section 774 of the Radon Registration Act requires registration to perform or evaluate radon tests, and the exemption in section 776 covers a person testing a building they own or inhabit that is not for sale at the time. As the buyer you neither own nor inhabit it, so the exemption does not reach you.

Does the seller have to test for radon before selling a house in Maine?

No. The statute requires disclosure, not testing. Under 33 M.R.S. § 173 the seller gives you a property disclosure statement that includes radon among its hazardous-materials items, and if the air or water was tested for radon in the two years before the transaction, the seller discloses those results. A seller who never tested has no result to disclose, and a blank on that line is not evidence about the property.

Do I need a separate radon test for the water if the home has a well?

Yes, if you want to know. Maine CDC describes them as separate measurements: the air test measures what is in the indoor air without identifying how it got there, and the water test is the one recommended for a home on a drilled well. One result does not predict the other, so an air test on a well home answers half the question.

Will my mortgage lender make me fix a radon result?

Radon testing is not part of what a standard purchase loan asks about a property. The loan's questions about a home on a private system are about safe, available water and safe sewage disposal, which is separate testing with its own rules. Radon is part of your inspection contingency instead, so whether anything gets done, and who pays for it, is negotiated between you and the seller rather than required by the file.

Who fixes radon in the water compared with radon in the air?

Different providers, and both have to be registered under section 775 to offer advice, plans, or contracted work to reduce radon. An air system is built onto the home to draw soil gas from under it and vent it. A water system is equipment plumbed into the water line, either aeration or a granular activated carbon unit that Maine CDC publishes guidance on. Expect two quotes from two trades if both come back needing attention.