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Radon Levels in Wells County, Indiana

EPA puts Wells County in Zone 1, its highest radon zone, and high results are common there: 47.8% of the 161 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

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    47.8%

    8.9 pts above IN

    Wells
    47.8%
    Indiana
    38.9%

    161 tests, 2008 to 2017

  • Median result

    3.6pCi/L

    Below action level

    Wells
    3.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    161

    33rd of 69 by tests

    Wells
    161
    St. Joseph
    7,346

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in Indiana

    23 of 69

    Middle half

    Wells
    47.8%
    Miami
    63.3%

    By share, of 69 with 30+ tests

Read a result for Wells County

Starts at Wells County's median, 3.6 pCi/L

3.6pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 3.6 pCi/L

Between 2 and 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Wells County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Wells County, At a glance

Wells County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Wells County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

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 Wells County, 2008 to 2017, laboratory

Reported results by concentration band, Wells County, 2008 to 2017, laboratory
Under 2 pCi/L: 22%2 to 4 pCi/L: 30%4 pCi/L and above: 48%

Of 161 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Wells County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L3521.7%
2 to 4 pCi/L4930.4%
4 pCi/L and above7747.8%
What these figures count

These are the 161 tests reported to CDC for Wells 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).

How to read these figures

Wells County, Compared

Wells County radon figures, compared

Calculated by Radon411

In Wells County, about 5 in 10 reported tests over the 2008 to 2017 laboratory totals (77 of 161) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 12.1 points higher. Across 92 Indiana counties pooled together, 38.9% of tests reached that level, so Wells County runs 8.9 points above its state.

Of 4 neighbours with a figure, 2 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 41.8% (Allen County) to 58.2% (Grant County). By share, Wells County is 23rd of 69 Indiana counties with 30 or more tests for the same period.

Half the tests came in under 3.6 pCi/L and half over it; the single highest reached 86.5 pCi/L. Below the action level, 35 tests (21.7%) came in under 2 pCi/L, against 32.8% statewide, and 49 tests (30.4%) fell between 2 and 4, against 28.3% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 47.8% share point the same way here. USGS geology rates 100% of the county's land high radon potential. CDC also counts 15 tests taken after mitigation in Wells County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Wells County went from 118 tests (2005 to 2014) to 161 (2008 to 2017), the share going from 51.7% to 47.8%.

Wells County against Indiana, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Wells County
Wells County16147.8%3.6 pCi/LThis county
Indiana, pooled92 counties, pooled43,14838.9%Not pooled−8.9 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−12.1 points
Miami Countyhighest in the state3063.3%5.3 pCi/L+15.5 points
Jasper Countylowest in the state7114.1%1.2 pCi/L−33.7 points
Grant County, INborders it7958.2%4.6 pCi/L+10.4 points
Adams County, INborders it6648.5%3.8 pCi/L+0.7 points
Jay County, INborders it944.4%2.7 pCi/L−3.4 points
Huntington County, INborders it16943.8%3.5 pCi/L−4.0 points
Allen County, INborders it3,99041.8%3.3 pCi/L−6.0 points
Blackford County, INborders it1136.4%3.6 pCi/L−11.4 points
Where Wells County's reported results fell, 2008 to 2017, laboratory, beside Indiana and the United States
ResultWells County testsWells County shareIndiana shareU.S. shareAgainst Indiana
Under 2 pCi/L3521.7%32.8%39.6%−11.1 points
2 to 4 pCi/L4930.4%28.3%24.7%+2.1 points
4 pCi/L and above7747.8%38.9%35.7%+8.9 points
Wells County ranked among the 69 Indiana counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Tipton County18 of 696949.3%3.9 pCi/L
Howard County19 of 6921649.1%3.8 pCi/L
Madison County20 of 6923949.0%3.8 pCi/L
Bartholomew County21 of 691,70748.7%3.9 pCi/L
Adams County22 of 696648.5%3.8 pCi/L
Wells County23 of 6916147.8%3.6 pCi/L
Clark County24 of 6951247.7%3.6 pCi/L
Porter County25 of 691,13646.5%3.5 pCi/L
Fulton County26 of 699746.4%3.3 pCi/L
Elkhart County27 of 692,85646.4%3.7 pCi/L
Clinton County28 of 698545.9%3.5 pCi/L
Wells County ten-year laboratory totals, against Indiana's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIndiana, pooledChange from the row before
2008 to 201716147.8%3.6 pCi/L86.5 pCi/L38.9%−5.5 points
2007 to 201613553.3%4.1 pCi/L86.5 pCi/L39.2%+1.8 points
2006 to 201513051.5%4.0 pCi/L86.5 pCi/L39.6%−0.2 points
2005 to 201411851.7%4.0 pCi/L86.5 pCi/L39.3%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Wells County, Geology

The ground under Wells County

Predicted

USGS's geologic map puts all of Wells County's mapped land in one class: high radon potential. All of it lies in the area the map calls Huron-Erie Lobe, to which USGS gives a radon index of 13, in the high band (12 to 17).

USGS's geologic areas under Wells County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Huron-Erie LobeCalcareous clayey and loamy glacial deposits derived from marine carbonate and clastic sedimentary rocks.High13100%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Wells County beside the ground around it

Wells County has more high-potential ground than Indiana as a whole: 100% of its land against 56.6%. Of the 6 counties that border it, none has as large a share of high-potential ground; Adams County comes nearest at 100%.

Share of land by USGS radon potential: Wells County, the 6 counties bordering it and Indiana
AreaEPA zoneLow potentialModerate potentialHigh potential
Wells CountyZone 1NoneNone100%
Adams CountyZone 1NoneNone100%
Huntington CountyZone 1NoneNone100%
Allen CountyZone 1NoneNone100%
Blackford CountyZone 1NoneNone100%
Jay CountyZone 1NoneNone100%
Grant CountyZone 1NoneNone100%
Indiana92 counties, pooled by land areaVariesNone43.4%56.6%

The map rates the ground, not the air in any home.

Local help

Wells County, Local resources

Radon testing and mitigation in Wells County

What Indiana's program says
Phone
1-800-272-9723
Licensing of radon professionals
According to the Indiana Radon Rule, 410 IAC 5.1, everyone who is serving Indiana by doing radon testing, analysis and mitigation (radon reduction) in residential structures must be certified by the Indiana State Department of Health.

What it means

Wells County, Questions

Questions about radon in Wells County

Are radon levels high in Wells County?

Over the 2008 to 2017 laboratory totals, 47.8% of the radon tests reported to CDC for Wells County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.6 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 22 reported a higher share; pooled, the state comes to 38.9%.

Which counties border Wells County?

Wells County borders 6 counties: Adams County, Huntington County, Allen County, Blackford County, Jay County and Grant County.

Products

Wells County, Products

Testing a home in Wells County

In Wells County, 47.8% of 161 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 38.9% pooled across Indiana. In Zone 1 the year-round level in Wells 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

Wells County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Wells County

Explore

Wells County, Bordering counties

Counties bordering Wells County

Calculated by Radon411

Wells County, Cities and towns

Cities and towns in Wells County

The Census Bureau estimates 28,883 residents in Wells County for July 1, 2025, 722 more than in 2020 (+2.6%). That works out to 78 people per square mile of land. Its largest town, Bluffton, has 10,583 residents, 36.6% of the total. CDC's 161 reported tests for 2008 to 2017 work out to 5.6 per 1,000 residents (2025 estimate), close to Indiana's 6.2.

From Bluffton to Vera Cruz, CDC publishes no figure by town: each reads Wells County's.

The cities and towns in Wells County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Bluffton10,583+2.7%36.6%
Ossian3,448+2.7%11.9%
Markleextends beyond Wells County1,086+1.5%Counted whole
Zanesvilleextends beyond Wells County600+3.3%Counted whole
Uniondale274+1.1%0.9%
Poneto178+2.3%0.6%
Vera Cruz71+2.9%0.2%

7 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Wells County is counted whole, so it has no share.

Wells County, Homes

Homes in Wells County

Wells County is a place of houses on their own lots: 78% of its 12,003 homes are detached single-family houses, against 73% across Indiana. Half of its homes were built before 1972, close to Indiana's 1976: 39% date from before 1960 and 14% from 2000 or later. Owners live in 76% of the occupied homes (Indiana: 70%), so for most households a test and a fix are their own to order.

Homes in Wells County, Indiana, 2019 to 2023
HomesWells CountyIndiana
Housing units12,0032,953,344
Detached houses78%73%
In buildings of 5 or more7%13%
Mobile homes7%4%
Built before 196039%32%
Built since 200014%21%
Middle year built19721976
Owner-occupied76%70%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.