Knox County is an EPA Zone 1 radon county, the highest risk category there is. Find out your home's number, and if it's high, fix it permanently with a system guaranteed to work.
Tell us about your property — we'll respond the same business day.
EPA's highest radon risk category — all of Knox County
guaranteed post-mitigation level (pCi/L)
typical mitigation system installation
Knoxville-based, serving all of Knox County & East Tennessee
From a single home test to building-wide multifamily programs — measured properly, fixed permanently, documented in writing.
Certified continuous-monitor testing with 48-hour results. Know your number before you finish a basement, or just for peace of mind.
Learn more →Sub-slab depressurization systems installed in a day, guaranteed below the EPA action level, verified with a follow-up test.
Learn more →Tamper-resistant tests built for inspection windows, with same-day reporting your agent can put straight in the file.
Learn more →Protocol-based testing and mitigation for apartments, daycares, schools and offices, with lender-ready documentation.
Learn more →Radon is a colorless, odorless radioactive gas produced by the natural breakdown of uranium in rock and soil. The Valley and Ridge geology under Knoxville is fractured limestone, shale and dolomite, shot through with the sinkholes and solution channels that come with karst terrain. That is close to a perfect delivery system for soil gas. Radon rides up through the fractures, enters homes through slab cracks, sump pits, crawlspace floors and utility penetrations, and collects in the lowest occupied level of the house.
The EPA places all of Knox County in Radon Zone 1, its highest category, meaning the predicted average indoor screening level for the county exceeds the 4.0 pCi/L action level. Neighboring Anderson, Blount, Loudon and Union counties carry the same designation. That is a county-wide prediction, not a promise about your address. Two identical houses on the same street in Farragut or Fountain City can test completely differently, because what matters is the fracture pattern under your particular foundation.
The health case is not marketing. The EPA attributes roughly 21,000 lung cancer deaths a year in the United States to radon, which makes it the second leading cause of lung cancer overall and the leading cause among people who have never smoked. Risk rises with both concentration and years of exposure, which is why the action threshold is 4.0 pCi/L and why the Surgeon General recommends testing every home below the third floor.
The useful part is that radon is the rare household hazard with a cheap answer at both ends. A test tells you exactly where you stand. A mitigation system, usually installed in one day for $900 to $2,500, reliably cuts levels by 80 to 99 percent. If your number comes back low, we will tell you so and you will not hear a sales pitch.
Straight answers to what Knoxville homeowners ask most.
Most systems run $900 to $2,500 depending on foundation type (basement, crawlspace, slab) and how far the pipe has to travel. Testing is typically $150 or less and is credited toward a system if we install one. Quotes are fixed, written and free.
Knox County is EPA Radon Zone 1, the highest of three zones. That is a county-level prediction that the average indoor screening level exceeds 4.0 pCi/L. It is still house by house, and the only way to know yours is to test.
No. Tennessee has no radon testing mandate. What it does have is a disclosure duty: under the Residential Property Disclosure Act, sellers of one to four unit homes must disclose what they know about environmental hazards, and radon is named on the standard form. A known high result must be disclosed. See our Tennessee disclosure guide.
The EPA recommends fixing at or above 4.0 pCi/L and considering action from 2.0. There is no truly safe threshold, because risk scales smoothly with exposure, which is why good mitigation targets the lowest achievable number, usually under 2.0.
Monitor placement within a day or two, a 48-hour test, results the same day it is picked up. Tell us your inspection deadline when you call. Real estate windows get priority. More on the real estate page.
Yes. Crawlspace homes accumulate radon too, and they are common across Knox County. Mitigation uses a sealed vapor barrier with sub-membrane suction instead of a slab penetration, and it works just as well.
Free quotes · Same-week testing · Serving Knoxville, Farragut, Powell, Halls, Karns, Bearden, Seymour, Oak Ridge & Maryville
Call (865) 563-8112Knox County sits in EPA Zone 1, so failed tests are routine rather than rare.
Most tests are booked around a closing date, so scheduling works backward from your deadline.
Sealing entry points is part of the install, not an upsell.
Radon rides in through cracks, joints and open sump pits. The system is designed around what we find.