Do you need to test for radon when you buy a house in Manchester, NH?

Do you need to test for radon when you buy a house in Manchester, NH? New Hampshire doesn't require a radon test when you buy a house, but it's worth doing here. Radon is a natural gas that comes up from New Hampshire's granite, and more than a third of homes tested come in high.

If you're buying your first house in Manchester, radon is probably one of those words you've heard but never really had explained. It shows up in the paperwork, somebody mentions a test, and it's easy to just nod along.

So let's start with what it actually is. Once you know why it's such a New Hampshire thing, the testing part makes a lot more sense.

What is radon?

Radon is a gas. You can't see it, smell it or taste it. It comes from uranium breaking down naturally in rock and soil, and it works its way up through the ground and into houses, through cracks in a foundation or gaps around pipes.

Outside, it spreads out and doesn't amount to much. Inside a closed-up house, it can build up.

And it matters. Nationally, radon is the second leading cause of lung cancer, and the NH Department of Health and Human Services estimates it's behind about 100 lung cancer deaths a year in New Hampshire. It's a long-term exposure thing, and it's fixable. But the only way to know what's in a house is to test it.

Why is radon higher in New Hampshire?

It comes down to what's under us. New Hampshire is the Granite State for a reason, and that granite, and the soil around it, carries uranium. As the uranium breaks down, it gives off radon.

Radon is measured in picocuries per liter of air, pCi/L. You don't need to remember the unit. The number to know is 4. That's the level where the EPA recommends fixing a home.

It's usually highest on the lowest level of the house, which for most of us is the basement. That's the part closest to the ground, where radon gets in. But it doesn't just stay down there. It moves through the house with the air, so the main floor isn't automatically in the clear.

Here's where New Hampshire lands. The average radon level in New Hampshire homes that have been tested is 1.8 pCi/L, compared with 1.25 nationally. And in state testing data from 2007 through 2021, 37% of homes tested came in at 4 pCi/L or higher.

Right next door to Manchester, it runs higher still. In Rockingham County, which includes Auburn, Derry and Londonderry, half of the homes tested came in at 7.9 pCi/L or higher.

And here's the part that surprises people: two houses on the same street can test completely differently. It depends on the soil right under the house, the foundation, and how it was built and sealed. So your neighbor's result doesn't tell you anything about the house you're buying.

So if radon is this common, why doesn't New Hampshire require a test?

New Hampshire's radon law, RSA 477:4-a, is a notice law, not a testing law. Before you sign a purchase and sale agreement, the seller or the seller's agent has to give you this notice, word for word:

"Radon, the product of decay of radioactive materials in rock, may be found in some areas of New Hampshire. Radon gas may pass into a structure through the ground or through water from a deep well. Testing of the air by a professional certified in radon testing and testing of the water by an accredited laboratory can establish radon's presence and equipment is available to remove it from the air or water."

It tells you radon can be in a house, and that testing exists. It doesn't require anyone to test. And the same law says the seller isn't on the hook if the notice never gets handed over. The NH Department of Health and Human Services says it plainly: state law doesn't require radon testing when a home sells.

So the test is up to you. And in a state where more than a third of the homes tested come in high, being told radon might be there and actually knowing are two very different things.

Air or water: which radon test do you need?

Radon can get into a house two ways. Most of it comes up through the ground and into the air. That's what most people mean when they say "radon test."

But if the house is on a private well, radon can also come in through the water. It gets released into the air every time you run a sink, take a shower or flush a toilet.

They're two separate tests, and they're two separate lines in the inspection section of the New Hampshire purchase and sale agreement.

Here's where Manchester makes it simpler. Most homes in the city are on Manchester Water Works, which draws mainly from Lake Massabesic. Radon in water is a private-well issue. It comes from groundwater moving through rock, and lake water gives its radon off into the air long before it reaches your tap. So on city water, the air test is the one that matters.

On a private well, both matter. Manchester Water Works also serves parts of Auburn, Bedford, Derry, Goffstown, Hooksett, Litchfield and Londonderry, so in the towns around Manchester it's worth checking whether a house is on town water or a well. For well water, NH DHHS says treating the water may make sense between 2,000 and 10,000 pCi/L if the air in the house is also above 4, and treating the water along with the air is the call at 10,000 or higher.

How does a radon test work when you're buying a house?

It happens during your inspection period, alongside your home inspection. The air test is done by a professional certified in radon testing, and a water test goes to an accredited lab.

For the air test, the monitor goes in the lowest level of the house that could be used regularly, finished or not. For most houses, that's the basement. It runs for at least 48 hours, and the house stays closed up, with windows shut and doors closed except for coming and going, starting 12 hours before the test and through the whole thing.

What happens if the radon test comes back high?

It gets negotiated just like any other concern on an inspection. And if the seller didn't disclose that it was high, it's easy to justify as a significant issue, because it's a health and safety issue.

That leaves you with the same three options you have with anything an inspection turns up:

• Accept it as it is.

• Have the seller fix it by putting in a mitigation system before closing.

• Get a credit for the cost of putting in a system after closing, either as a reduction in the sale price or as a concession toward your closing costs.

In my experience, the average air mitigation system runs around $1,500. A water system depends on the individual house. Either way, knowing about it before you close means you can budget to fix it yourself, or have it taken care of by the seller.

Radon isn't one and done

Testing when you buy and thinking you're good forever is not the play. Radon levels change, day to day and season to season, so one test is a snapshot. The EPA recommends retesting at least every two years.

If a mitigation system goes in, whether the seller installs it or you do after closing, test again once it's running. The EPA says within 30 days of installation, to make sure it's actually doing its job.

And if you have a system, the fans do burn out. The EPA says they typically last five years or more, and most warranties don't go past five. So make sure you're regularly checking that it's working. Every system is required to have a warning device, usually a small liquid gauge on the pipe, sometimes an alarm or a light, and a quick look at it is the easiest way to know.

Buying a house that already has a system? Ask the seller for whatever information they have on it, and make sure it's running during your test.

Frequently asked questions

Is radon testing required when you buy a house in New Hampshire? No. RSA 477:4-a requires the seller or the seller's agent to give you a radon notice before you sign a purchase and sale agreement, but no one is required to test. Whether you test during your inspection period is up to you.

Do homes on Manchester city water need a radon water test? Usually not. Radon in water is a private-well issue, and Manchester Water Works draws mainly from Lake Massabesic, which gives its radon off into the air before it reaches your tap. So on city water, the air test is the one that matters. On a private well, which is common in some of the towns around Manchester, test both the air and the water.

How often should you test for radon after you buy? The EPA recommends retesting at least every two years, and again within 30 days of a mitigation system being installed. The NH Radon Program offers free test kits to New Hampshire residents, so retesting after you move in doesn't have to cost anything.

Buying your first house in Manchester and want to talk through radon, inspections, or any of it? Call or text Jess Provencher, Broker/Owner at Pro Homes, at 603-519-3310 or visit prohomesnh.com. Serving Manchester and the towns around it: Bedford, Goffstown, Hooksett, Auburn, Londonderry, Derry and Concord.