Radon in Northern Utah Homes: Testing, Risks, and What You Can Do

There’s a hazard in thousands of Northern Utah homes that you can’t see, smell, or taste. It doesn’t set off any alarm. It builds up slowly and silently, and long-term exposure is the second leading cause of lung cancer in the United States — responsible for an estimated 21,000 deaths every year. It’s radon, and if you live along the Wasatch Front, the odds are uncomfortably high that it’s in your home right now.

This isn’t fearmongering. It’s geology. The same soil conditions that give Northern Utah its spectacular mountain scenery also produce some of the highest residential radon levels in the country. Roughly one in three Utah homes tested exceed the EPA’s recommended action level of 4 picocuries per liter (pCi/L), and some homes in our area have tested at 10, 15, even 20+ pCi/L — levels that represent serious, measurable health risk with prolonged exposure.

The good news is that radon is straightforward to test for and very effectively mitigated once identified. The challenge is that most homeowners either don’t know about the risk or assume it doesn’t apply to them. This article will give you the facts, explain what to do, and point you toward resources — several of them free — that can help you protect your family.

Key Takeaways

Roughly 1 in 3 Utah homes tested exceed the EPA’s recommended action level of 4 pCi/L (picocuries per liter), with some homes testing at 10-20+ pCi/L.

Short-term radon test kits are available for approximately $8 through radon.utah.gov, and the Davis County Health Department offers free test kits during winter months (November through March).

Radon mitigation costs approximately $500 during new construction versus $1,200-$1,700 as a retrofit in an existing home — a sub-slab depressurization system typically reduces levels by 80-99%.

Utah’s HB 17 (2022) requires anyone who installs, repairs, or maintains a radon mitigation system to hold a valid Utah radon mitigation license.

Utah omitted IRC Appendix F from its building code, meaning builders are not required to include radon-resistant features in new homes, even in high-risk areas.

What Radon Is and Where It Comes From

Radon is a naturally occurring radioactive gas produced by the decay of uranium in soil, rock, and groundwater. Uranium is present in varying concentrations in soil and bedrock everywhere, but certain geological formations produce significantly more radon than others.

Northern Utah sits at the intersection of several radon-producing conditions:

Uranium-bearing geological formations in the Wasatch Range and surrounding areas
Lake Bonneville sediment deposits that contain uranium-bearing minerals
Fractured bedrock along the Wasatch Fault that allows radon to migrate upward more easily
Well-drained, permeable soils in many areas that don’t trap radon underground

Radon gas seeps up through the soil and enters homes through any pathway it can find — cracks in foundation slabs, gaps around pipes and utility penetrations, sump pump openings, crawl spaces, and even through concrete block walls (which are porous enough to allow gas migration). Once inside, it accumulates. Because modern homes are increasingly well-sealed for energy efficiency, radon can build to high concentrations without adequate ventilation.

Why Radon Is Dangerous

When you breathe in radon gas, it decays inside your lungs, releasing alpha particles that damage lung tissue at the cellular level. Unlike a single acute exposure, radon damage is cumulative. It’s the total exposure over time — the concentration level multiplied by the duration of exposure — that determines risk.

The EPA has established 4 pCi/L as the action level — the concentration above which they recommend homeowners take steps to reduce radon levels. To put that in perspective:

4 pCi/L carries roughly the same lung cancer risk as smoking half a pack of cigarettes per day
8 pCi/L is comparable to smoking a pack a day
20 pCi/L (which some Utah homes have tested at) is equivalent to having 2,000 chest X-rays per year

These are EPA’s own comparisons, and they underscore why this isn’t something to dismiss or put off. Radon-induced lung cancer typically develops over 5-25 years of exposure, and it affects non-smokers as well as smokers (though smokers are at significantly higher risk due to the compounding effects).

Northern Utah’s Radon Landscape

The Utah Department of Environmental Quality maintains radon data by county and ZIP code. Here’s what the data shows for our area:

High-risk areas (Zone 1 — predicted average indoor radon above 4 pCi/L):

Davis County
Weber County
Salt Lake County (portions)
Utah County (portions)
Morgan County
Summit County

Davis County in particular has some of the highest radon levels along the Wasatch Front. Communities like Farmington, Kaysville, Layton, Clearfield, and Bountiful frequently test above the action level. Weber County — Ogden, Roy, Riverdale, North Ogden — is similarly affected.

But radon is notoriously variable. Two houses on the same street can have dramatically different levels because of differences in soil composition, foundation type, and air pressure dynamics. You genuinely cannot predict your home’s radon level based on your neighbor’s results. The only way to know is to test.

How to Test Your Home

Radon testing is simple, inexpensive, and something any homeowner can do.

Short-Term Testing (2-7 Days)

The most common starting point is a charcoal canister or alpha track detector placed in the lowest livable level of your home (typically a basement) for 2-7 days. These test kits are widely available:

Utah Department of Environmental Quality: Kits available for approximately $8 through radon.utah.gov. You mail the kit to a lab after the exposure period and receive results within a few weeks.
Hardware stores: Home Depot, Lowe’s, and similar retailers carry short-term test kits for $10-$20.
Davis County Health Department: Offers FREE radon test kits during winter months (November through March). Call (801) 525-5128 to request one. This is an exceptional resource if you live in Davis County — take advantage of it.

Testing best practices:

Test during the heating season (October through March) when homes are closed up and radon levels are typically highest
Place the test in the lowest livable level — if you use your basement, test there
Keep windows and exterior doors closed as much as practical during the test period (normal entry and exit is fine)
Don’t place the test in a kitchen, bathroom, or laundry room — humidity and air movement in these spaces can skew results
Place it at least 20 inches off the floor and away from exterior walls

Long-Term Testing (90+ Days)

If your short-term test comes back between 2 and 4 pCi/L, or if you want a more accurate picture of your year-round exposure, a long-term test (90 days to one year) provides a better average. Alpha track detectors are the most common long-term testing device.

Professional Testing

If you’re buying or selling a home, many real estate transactions involve professional radon testing performed by a certified measurement professional. Professional testing typically uses continuous radon monitors (CRMs) that log radon levels every hour for 48+ hours and provide detailed data. Cost is typically $150-$300.

What to Do If Your Level Is High

If your test results come back at or above 4 pCi/L, the EPA recommends taking action to reduce radon levels. The standard approach is a sub-slab depressurization system (also called active soil depressurization or ASD). Here’s how it works:

A hole is cored through the basement slab into the gravel or soil beneath
A PVC pipe is sealed into the hole and routed up through the house and out through the roof (similar to a plumbing vent)
A specialized inline fan mounted in the attic or on the exterior creates a slight vacuum beneath the slab
This vacuum continuously draws radon-laden soil gas from beneath the foundation and exhausts it above the roofline, where it disperses harmlessly in the atmosphere

The system runs 24/7, is quiet (about as loud as a bathroom exhaust fan), and typically costs $1,200 to $1,700 installed as a retrofit in an existing home.

For new construction, a radon-resistant system (passive pipe through the slab with the option to add a fan later) can be installed during construction for approximately $500 — a fraction of the retrofit cost. We’ll talk more about new construction in a moment.

After installation, you should re-test to confirm the system is working. A properly designed mitigation system typically reduces radon levels by 80-99%, often bringing levels well below 2 pCi/L.

Radon Levels, Risk, and Recommended Actions

Radon Level (pCi/L)	Risk Category	Recommended Action	Comparable Risk
Below 2	Low risk	No action needed; re-test every 5 years	Minimal additional lung cancer risk
2 - 4	Moderate risk	Consider mitigation, especially if lowest level is occupied; long-term test recommended	Equivalent to 200+ chest X-rays/year
4 - 8 (EPA action level)	Elevated risk	Mitigate — install sub-slab depressurization ($1,200-$1,700 retrofit)	Comparable to smoking half a pack of cigarettes/day
8 - 10	High risk	Mitigate promptly — prioritize within weeks, not months	Comparable to smoking a pack of cigarettes/day
Above 10	Urgent risk	Mitigate immediately — limit time in lowest level until system is installed	Equivalent to 2,000+ chest X-rays/year at 20 pCi/L

Testing & Mitigation Option	Cost	Notes
DIY short-term test kit (radon.utah.gov)	~$8	Mail-in charcoal canister; results in 2-3 weeks
Davis County free winter kit	Free (Nov-Mar)	Call (801) 525-5128 to request
Retail test kit (Home Depot, Lowe’s)	$10-$20	Charcoal or alpha track detector
Professional CRM testing	$150-$300	Continuous radon monitor; hourly data for 48+ hours
New construction radon-resistant pipe	~$500	Passive pipe through slab; fan added later if needed
Retrofit mitigation (sub-slab depressurization)	$1,200-$1,700	Active fan system; reduces levels 80-99%

Water heater and filtration system installation in a Northern Utah basement utility area

The Basement Factor

This is critically important for Northern Utah homeowners, where finishing basements is practically a rite of passage. Finishing a basement changes your home’s radon profile.

When you finish a basement — adding walls, flooring, and HVAC connections — you change the air pressure dynamics and ventilation patterns in the lowest level of the house. A home that tested at acceptable radon levels with an unfinished basement may test significantly higher after the basement is finished, because:

You’ve reduced natural ventilation that was diluting radon
You’ve sealed pathways (cracks, gaps) that were allowing some radon to dissipate
You’ve created a living space where family members now spend significant time, increasing exposure even if concentrations remain the same

Always re-test for radon after finishing a basement. This is true even if you tested years ago and the results were fine. The conditions have changed, and your family is now spending time in that lowest level.

Similarly, if you’ve made significant changes to your home’s envelope — new windows, air sealing, insulation upgrades — these energy-efficiency improvements can also increase radon accumulation by reducing air exchange. Re-test after major weatherization work.

Utah’s Building Code Gap

Here’s something that frustrates those of us in the home services industry. Utah adopted the 2015 International Residential Code (IRC) as the basis for its state building code, but it omitted Appendix F, which covers radon-resistant new construction (RRNC).

Appendix F is an optional appendix in the IRC that provides requirements for installing radon-resistant features during new construction — things like a gas-permeable layer beneath the slab, sealed penetrations, and a passive vent pipe that can easily be activated with a fan if testing reveals elevated radon.

Because Utah omitted this appendix, builders are not required to include radon-resistant features in new homes, even in areas known to have high radon levels. Some builders voluntarily include them (and it’s absolutely worth asking), but many don’t.

The cost difference is stark: $500 during construction vs. $1,200-$1,700 as a retrofit. If you’re building a new home anywhere along the Wasatch Front, insist on radon-resistant construction. It’s cheap insurance, and if testing later shows you don’t need it, you’ve spent $500 on peace of mind. If testing shows you do need it, you’ve saved over a thousand dollars and the disruption of a retrofit.

If you’re buying a new-construction home, ask the builder directly: “Does this home include radon-resistant construction features per IRC Appendix F?” If the answer is no, negotiate for it. It’s a minor cost in the context of a new home purchase.

HB 17: Radon Mitigation Licensing

In 2022, Utah passed House Bill 17, which established a licensing requirement for radon mitigation contractors. Under this law, anyone who installs, repairs, or maintains a radon mitigation system in Utah must hold a valid radon mitigation license.

This is a positive development. Radon mitigation is not complicated in concept, but proper system design matters — the fan size, pipe routing, sealing of the slab penetration, and proper exhaust location all affect whether the system actually achieves the necessary reduction. A poorly designed or installed system can fail to adequately reduce radon levels, or worse, create other problems like backdrafting of combustion appliances.

When hiring a radon mitigation contractor, verify their Utah license and ask about their post-installation testing protocol. A reputable contractor will always re-test after installation to verify the system is performing as designed.

Radon and Real Estate

If you’re buying or selling a home in Northern Utah, radon should be part of the conversation.

For buyers:

Request radon testing as part of your due diligence period
If levels are elevated, request mitigation as part of your purchase negotiation — it’s a reasonable and common request
Don’t skip testing just because the home is newer. New homes can have high radon too
Remember that a previous test result may not reflect current conditions, especially if the home has been modified

For sellers:

Consider testing proactively before listing. If levels are elevated, mitigating before you list removes a potential negotiation point and shows good faith
Disclosure requirements vary, but if you’ve tested and found elevated levels, you should disclose that information

Real estate agents along the Wasatch Front are increasingly aware of radon issues, but not all buyers’ agents will proactively recommend testing. Take the initiative yourself.

Protecting Your Family: A Step-by-Step Plan

Test your home. Start with a short-term test kit from radon.utah.gov ($8) or your county health department. If you’re in Davis County, get a free kit from November through March by calling (801) 525-5128.
If results are 4 pCi/L or above, hire a licensed radon mitigation contractor to install a sub-slab depressurization system. Budget $1,200-$1,700 for a typical residential installation.
If results are 2-4 pCi/L, consider a long-term test (90+ days) to get a more accurate average. The EPA recommends considering mitigation at these levels as well, especially if you spend significant time in the lowest level.
If results are below 2 pCi/L, you’re in good shape. Re-test every 5 years, or sooner if you make significant changes to the home (finishing a basement, major air sealing, etc.).
If you’re building or buying new construction, insist on radon-resistant features. It’s the single cheapest time to address the issue.

Frequently Asked Questions

Can I just open a window to reduce radon? Temporarily, yes — opening windows in the lowest level will dilute radon with outdoor air. But it’s not a practical long-term solution. In Utah winters, you’re not going to leave basement windows open when it’s 15 degrees outside. And as soon as you close them, radon begins accumulating again. A mitigation system works 24/7 regardless of weather.

My home is built on a crawl space, not a slab. Am I at risk? Yes. Radon enters through crawl spaces as well, and a vented crawl space may have lower radon levels than a sealed one — but neither is guaranteed to be safe. Crawl space homes can be effectively mitigated, though the approach may differ slightly from slab-on-grade construction. Test regardless of foundation type.

Does a radon mitigation system increase my energy costs? The fan draws about 30-90 watts continuously depending on the model, comparable to a light bulb. Annual electricity cost is roughly $30-$80. Because the system creates a slight negative pressure beneath the slab, it can marginally increase heating costs, but the effect is minimal and far outweighed by the health benefit.

Is radon only a problem in winter? Radon is present year-round, but indoor levels are typically highest in winter when homes are closed up and the stack effect (warm air rising inside the home) draws more soil gas in through the foundation. Testing during winter gives you a reading close to your peak exposure. Summer levels are usually lower but not zero.

Take the First Step

Radon is one of those issues where knowledge really is power. An $8 test kit can tell you whether your family is being exposed to a serious carcinogen — and if they are, the fix is straightforward and affordable. There’s no reason for any Northern Utah homeowner to live with elevated radon levels when testing is this simple and mitigation is this effective.

At All Things Home Services, we’re committed to helping families across Davis County, Weber County, Salt Lake County, and Utah County keep their homes safe. While we aren’t radon mitigation contractors, we work in homes across Northern Utah every day and understand how radon intersects with plumbing, HVAC, and overall home health. We’re happy to point you toward reputable testing and mitigation resources.

If you have questions about how a basement finishing project, HVAC modification, or other home improvement might affect your radon situation, contact us at (385) 401-9490. We’re here to help you make informed decisions about your home.