Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Fairfield County, Ohio
EPA puts Fairfield County in Zone 1, its highest radon zone, and high results are common there: 76.8% of the 1,175 radon tests reported to CDC (2008 to 2017, laboratory totals) came back at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
76.8%
24.5 pts above OH
- Fairfield
- 76.8%
- Ohio
- 52.3%
1,175 tests, 2008 to 2017
Median result
7.4pCi/L
Action level reached
- Fairfield
- 7.4 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
1,175
26th of 79 by tests
- Fairfield
- 1,175
- Franklin
- 16,142
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Ohio
2 of 79
Top quarter
- Fairfield
- 76.8%
- Pickaway
- 81.4%
By share, of 79 with 30+ tests
Read a result for Fairfield County
Starts at Fairfield County's median, 7.4 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 7.4 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Fairfield County's median reported result, 2008 to 2017.
The data
Fairfield County, At a glance
Fairfield County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Fairfield County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Fairfield County, 2008 to 2017, laboratory
Under 2 pCi/L: 9%2 to 4 pCi/L: 14%4 pCi/L and above: 77%
Of 1,175 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 110 | 9.4% |
| 2 to 4 pCi/L | 163 | 13.9% |
| 4 pCi/L and above | 902 | 76.8% |
What these figures count
These are the 1,175 tests reported to CDC for Fairfield County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Fairfield County, Compared
Fairfield County radon figures, compared
Calculated by Radon411More than half: 76.8% of the 1,175 radon tests reported to CDC for Fairfield County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 2nd of 79 Ohio counties with 30 or more tests for the same period. That is 24.5 points above the 52.3% pooled from 88 Ohio counties.
The median result, 7.4 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 481.8 pCi/L. The rest split 9.4% under 2 pCi/L and 13.9% from 2 to 4 (Ohio: 23.1% and 24.6%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 76.8% share point the same way here.
1 of its 5 bordering counties with figures ran higher, led by Pickaway County at 81.4%; Perry County reported 48.9%. Statewide for the same period, Pickaway County reported the highest share (81.4%) and Cuyahoga County the lowest (21.7%).
CDC's ten-year totals for Fairfield County went from 1,050 tests (2005 to 2014) to 1,175 (2008 to 2017), the share going from 72.3% to 76.8%.
Nationally, every county with a figure for the same period pools to 35.7%; Fairfield County sits 41.1 points above it. CDC also counts 118 tests taken after mitigation in Fairfield County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Fairfield County, Geology
The ground under Fairfield County
PredictedUSGS's geologic map puts all of Fairfield County's mapped land in one class: high radon potential. The map puts 80.4% of Fairfield County in the area it calls Till Plains and 13.9% in Glaciated Plateau, with one smaller area beside them. USGS gives the first a radon index of 14 and the second 12, both in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Till Plains | Glacial deposits underlain by Ordovician through Devonian limestone and shale. | High | 14 | 80.4% |
| Glaciated Plateau | Pre-Wisconsin glacial deposits derived from high radioactivity marine black shale. | High | 12 | 13.9% |
| Mississippian Limestone | Mississippian limestone exhibiting high gamma radioactivity. | High | 14 | 5.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Fairfield County beside the ground around it
Fairfield County has more high-potential ground than Ohio as a whole: 100% of its land against 62.8%. Of the 5 counties that border it, none has as large a share of high-potential ground; Franklin County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Fairfield County, Local resources
Radon testing and mitigation in Fairfield County
Listed radon businesses with an address in Fairfield County:
- Radon Education and Licensing ProgramRadon Education and Licensing Program, run by Ohio Department of Health, licenses or certifies radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Ohio.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Free radon test kits are available for Ohio homeowners.
- Compare kits
- Professionals in Ohio479 professionals are listed in Ohio.
Listed radon professionals by town: Columbus, Reynoldsburg, Lancaster, Pickerington, Canal Winchester, Baltimore, Pleasantville, Amanda, Stoutsville
What Ohio's program says
- Phone
- 614-728-0272
- indoor.radon@odh.ohio.gov
- Licensing of radon professionals
This program licenses companies and persons directly involved with the radon testing and mitigation industry.
What it means
Fairfield County, Questions
Questions about radon in Fairfield County
Are radon levels high in Fairfield County?
Over the 2008 to 2017 laboratory totals, 76.8% of the radon tests reported to CDC for Fairfield County, Ohio were at or above 4 pCi/L, and the median reported pre-mitigation result was 7.4 pCi/L. Of 79 Ohio counties with 30 or more tests for the same period, 1 reported a higher share; pooled, the state comes to 52.3%.
Which counties border Fairfield County?
Fairfield County borders 5 counties: Hocking County, Licking County, Perry County, Franklin County and Pickaway County.
Products
Fairfield County, Products
Testing a home in Fairfield County
In Fairfield County, 76.8% of 1,175 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 52.3% pooled across Ohio. In Zone 1 the year-round level in Fairfield County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
MonitorX-Sense
XR0A-iR Wi-Fi battery radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Wi-Fi
- Screen, app
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Fairfield County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Fairfield County
Explore
Fairfield County, Bordering counties
Counties bordering Fairfield County
Calculated by Radon411- Radon levels in Pickaway CountyEPA zone 1
81.4%at or above 4 pCi/L
Median 9.5 pCi/L · 183 tests · 4.6 points above Fairfield County
- Radon levels in Franklin CountyEPA zone 1
71.9%at or above 4 pCi/L
Median 6.8 pCi/L · 16,142 tests · 4.9 points below Fairfield County
- Radon levels in Licking CountyEPA zone 1
71.2%at or above 4 pCi/L
Median 7.0 pCi/L · 4,694 tests · 5.6 points below Fairfield County
- Radon levels in Hocking CountyEPA zone 2
53.3%at or above 4 pCi/L
Median 4.0 pCi/L · 60 tests · 23.5 points below Fairfield County
- Radon levels in Perry CountyEPA zone 1
48.9%at or above 4 pCi/L
Median 3.8 pCi/L · 90 tests · 27.9 points below Fairfield County
Fairfield County, Cities and towns
Cities and towns in Fairfield County
Fairfield County is growing: the Census Bureau puts it at 169,752 residents on July 1, 2025, up 6.5% from 159,451 in 2020. That works out to 337 people per square mile of land. Columbus, the largest place on its list (938,396 residents in all), extends beyond Fairfield County, so no share of the total is worked out for it. CDC's 1,175 reported tests for 2008 to 2017 work out to 6.9 per 1,000 residents (2025 estimate), close to Ohio's 8.3.
From Columbus to West Rushville, CDC publishes no figure by town: each reads Fairfield County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Columbusextends beyond Fairfield County | 938,396 | +3.5% | Counted whole |
| Reynoldsburgextends beyond Fairfield County | 43,350 | +5.6% | Counted whole |
| Lancaster | 41,956 | +3.2% | 24.7% |
| Pickeringtonextends beyond Fairfield County | 26,333 | +13.4% | Counted whole |
| Canal Winchesterextends beyond Fairfield County | 10,058 | +9.4% | Counted whole |
| Baltimore | 3,110 | +2.3% | 1.8% |
| Lithopolisextends beyond Fairfield County | 2,969 | +36.4% | Counted whole |
| Buckeye Lakeextends beyond Fairfield County | 2,590 | +2.5% | Counted whole |
| Bremen | 1,528 | +2.5% | 0.9% |
| Millersport | 1,008 | +3.1% | 0.6% |
| Pleasantville | 964 | +2.2% | 0.6% |
| Amanda | 680 | +2.1% | 0.4% |
Places in Fairfield County with a city page: 1 of 2
- Thurston
- Stoutsville
- Carroll
- Sugar Grove
- Rushville
- Tarlton (part)
- West Rushville
19 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Fairfield County is counted whole, so it has no share.
Fairfield County, Homes
Homes in Fairfield County
Fairfield County is a place of houses on their own lots: 78% of its 63,397 homes are detached single-family houses, against 69% across Ohio. Much of Fairfield County is recent building: 25% of its homes have gone up since 2000 and the middle year built is 1983, against 1970 for Ohio. 74% of occupied homes are lived in by their owner (Ohio: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Fairfield County | Ohio |
|---|---|---|
| Housing units | 63,397 | 5,271,573 |
| Detached houses | 78% | 69% |
| In buildings of 5 or more | 9% | 15% |
| Mobile homes | 2% | 4% |
| Built before 1960 | 26% | 38% |
| Built since 2000 | 25% | 16% |
| Middle year built | 1983 | 1970 |
| Owner-occupied | 74% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.