Northern Kentucky radon: a Boone, Kenton, and Campbell guide

Cross the Brent Spence or the Big Mac bridge and the radon map changes color. EPA's Map of Radon Zones shades Hamilton County red for Zone 1 and Boone, Kenton, and Campbell counties orange for Zone 2. That difference is real on paper and easy to over-read in a basement. Here is what the Kentucky side of the metro should know about the map, the state's rules, and testing a house you live in or are about to buy.

What Zone 2 means, and what it leaves out

EPA's zones are county predictions, built in 1993 from geology, aerial radioactivity, soils, foundation types, and the indoor measurements available at the time. Zone 2 means a predicted average indoor screening level between 2 and 4 pCi/L. It does not mean most houses fall in that band, and EPA says the map should not be used to decide whether a particular home needs a test. Pendleton County, just south of Campbell and Kenton, is mapped as Zone 1.

The University of Kentucky's BREATHE program, which produces county radon handouts, puts it plainly for all three counties: radon is a problem in many areas of Kentucky, including yours, and high levels can occur even where the geology suggests lower danger. Its radon data page also links an interactive statewide radon map from the Kentucky Geological Survey.

What Northern Kentucky lacks is the kind of ZIP-level test data Ohio publishes. Across the river, the Ohio Department of Health posts results from licensed professionals by ZIP code, and the Hamilton County numbers show about 22 percent of tests above 4.0 pCi/L. No equivalent public dashboard exists for Boone, Kenton, or Campbell, so the honest summary is that the Kentucky side has less measured data, not less radon. Our Ohio radon map by county lists the three Kentucky counties alongside Ohio's.

Kentucky's rules for who can test and fix a house

Kentucky regulates radon work under KRS 211.9101 to 211.9135. Since January 1, 2013, no person or business may perform radon measurement, mitigation, or laboratory analysis in the Commonwealth without the appropriate certification. Since a 2019 amendment, certification means holding a credential from one of the two national proficiency programs, NRPP or NRSB, plus a registration certificate from the Cabinet for Health and Family Services.

The same law sets insurance floors. Registered mitigation contractors must carry general liability coverage of at least $500,000, and measurement contractors at least $250,000. It also assigns duties that protect you:

• mitigation must follow the applicable standard operating procedures and be done under the direct supervision of a certified mitigation contractor
• the post-mitigation measurement must be made by a certified measurement contractor
• any system repaired or altered since 2013 must meet the applicable procedures

There are exemptions. A homeowner may test or fix the single-family house they own and live in, an owner may test a building they own, and a builder installing vent pipes during new construction is not covered. Anyone else who tests or mitigates for pay needs the certification. Ask for the Kentucky registration certificate and the NRPP or NRSB credential before anyone drills your floor.

Houses on the Kentucky side

The river cities of Covington, Newport, Bellevue, Dayton, and Ludlow hold much of Northern Kentucky's oldest housing, much of it brick, and many of those houses sit on basements cut into steep lots. Older basements tend to have more joints, patched floors, and utility holes than newer ones, and every one of those is a possible route for soil gas. The hillside setting adds walkout basements, where part of the floor is at grade and part is buried.

The ridge-top cities such as Fort Mitchell, Park Hills, Fort Wright, and Fort Thomas mix early twentieth century homes with postwar ranches and Cape Cods. Erlanger, Elsmere, and Edgewood carry large postwar neighborhoods, and the newer subdivisions around Florence, Union, and Hebron in Boone County and Independence in Kenton County add slab-on-grade and basement homes built in recent decades.

None of those eras is safe by default. EPA is clear that any home, old or new, drafty or tight, with or without a basement, may have a radon problem, and a slab-on-grade house still has a slab with joints and penetrations. The only way to sort one house from the next is the test.

Wells are rare here, and that changes the checklist

Radon in well water gets a lot of attention online, but it is a small concern for most Northern Kentucky households. The Kentucky Geological Survey's county groundwater reports estimated that about 92 percent of Kenton County residents and 94 percent in Campbell County were served by public water utilities in 2008, and about 80 percent in fast-growing Boone County. Where public water does not reach, KGS found that only around one household in ten used a well, with cisterns and hauled water covering the rest, and most drilled wells in the upland areas do not yield a dependable supply.

EPA's advice fits that picture. Test the air first, and consider a water test only if you are on a private well and the air result is high.

Testing during a Kentucky home sale

Most radon tests on this side of the river happen during a purchase, inside the inspection period in the contract. EPA's Home Buyer's and Seller's Guide accepts three short-term approaches for a transaction: two passive devices side by side for at least 48 hours, two passive tests run back to back, or a continuous monitor for at least 48 hours. Any of them should include steps to prevent or detect tampering, and the test belongs in the lowest level a buyer could use as living space.

If the result is 4.0 or higher, EPA recommends fixing the home, and the buyer and seller negotiate who pays and when. For homeowners who are not selling, a hardware-store kit or a measurement professional certified under Kentucky law is the starting point.

Next steps by town

We cover the Kentucky side as closely as the Ohio side. See radon testing in Fort Mitchell, Edgewood, and Crescent Springs, or start from the Covington area page. If a test is already back and high, our walk-through of how long mitigation takes lays out each step from the site visit to the verified retest. Call or text us with your number and your address, and we will tell you what the next week looks like.