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Radon Levels in Benton County, Indiana

EPA puts Benton County in Zone 1, its highest radon zone, and high results are common there: 61.8% of the 34 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

    61.8%

    22.9 pts above IN

    Benton
    61.8%
    Indiana
    38.9%

    34 tests, 2008 to 2017

  • Median result

    5.7pCi/L

    Action level reached

    Benton
    5.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    34

    68th of 69 by tests

    Benton
    34
    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

    3 of 69

    Top quarter

    Benton
    61.8%
    Miami
    63.3%

    By share, of 69 with 30+ tests

Read a result for Benton County

Starts at Benton County's median, 5.7 pCi/L

5.7pCi/L

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

EPA’s reading of 5.7 pCi/L

At or above 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 at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Benton County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Benton County, At a glance

Benton County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Benton 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 Benton County, 2008 to 2017, laboratory

Reported results by concentration band, Benton County, 2008 to 2017, laboratory
Under 2 pCi/L: 21%2 to 4 pCi/L: 17%4 pCi/L and above: 62%

Of 34 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Benton County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L720.6%
2 to 4 pCi/L617.6%
4 pCi/L and above2161.8%
What these figures count

These are the 34 tests reported to CDC for Benton 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

Benton County, Compared

Benton County radon figures, compared

Calculated by Radon411

More than half: 61.8% of the 34 radon tests reported to CDC for Benton County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 3rd of 69 Indiana counties with 30 or more tests for the same period. That is 22.9 points above the 38.9% pooled from 92 Indiana counties.

The median result, 5.7 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 43.4 pCi/L. The rest split 20.6% under 2 pCi/L and 17.6% from 2 to 4 (Indiana: 32.8% and 28.3%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 61.8% share point the same way here.

No bordering county with a figure for the same period reported a higher share; the closest is Vermilion County, IL at 48.8%, the lowest Jasper County at 14.1%. Statewide for the same period, Miami County reported the highest share (63.3%) and Jasper County the lowest (14.1%).

CDC's ten-year totals for Benton County went from 36 tests (2005 to 2014) to 34 (2008 to 2017), the share going from 58.3% to 61.8%.

Nationally, every county with a figure for the same period pools to 35.7%; Benton County sits 26.1 points above it.

Benton County against Indiana, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Benton County
Benton County3461.8%5.7 pCi/LThis county
Indiana, pooled92 counties, pooled43,14838.9%Not pooled−22.9 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−26.1 points
Miami Countyhighest in the state3063.3%5.3 pCi/L+1.5 points
Warrick Countylowest in the state56120.9%1.8 pCi/L−40.9 points
Vermilion County, ILborders it37948.8%3.8 pCi/L−13.0 points
Tippecanoe County, INborders it1,21836.8%2.7 pCi/L−25.0 points
White County, INborders it4235.7%2.7 pCi/L−26.1 points
Warren County, INborders it2733.3%3.5 pCi/L−28.5 points
Iroquois County, ILborders it41028.0%2.1 pCi/L−33.8 points
Jasper County, INborders it7114.1%1.2 pCi/L−47.7 points
Newton County, INborders it1612.5%1.6 pCi/L−49.3 points
Where Benton County's reported results fell, 2008 to 2017, laboratory, beside Indiana and the United States
ResultBenton County testsBenton County shareIndiana shareU.S. shareAgainst Indiana
Under 2 pCi/L720.6%32.8%39.6%−12.2 points
2 to 4 pCi/L617.6%28.3%24.7%−10.7 points
4 pCi/L and above2161.8%38.9%35.7%+22.9 points
Benton 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
Miami County1 of 693063.3%5.3 pCi/L
Harrison County2 of 6922162.4%5.5 pCi/L
Benton County3 of 693461.8%5.7 pCi/L
Carroll County4 of 693860.5%5.8 pCi/L
Wabash County5 of 699159.3%5.8 pCi/L
Grant County6 of 697958.2%4.6 pCi/L
LaPorte County7 of 6979258.2%5.0 pCi/L
DeKalb County8 of 6924256.6%4.4 pCi/L
Wayne County9 of 6914056.4%4.5 pCi/L
Steuben County10 of 6914055.7%4.5 pCi/L
Delaware County11 of 6918755.1%4.2 pCi/L
Benton County ten-year laboratory totals, against Indiana's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIndiana, pooledChange from the row before
2008 to 20173461.8%5.7 pCi/L43.4 pCi/L38.9%+1.8 points
2007 to 20163560.0%4.9 pCi/L43.4 pCi/L39.2%+2.9 points
2006 to 20153557.1%6.1 pCi/L43.4 pCi/L39.6%−1.2 points
2005 to 20143658.3%5.4 pCi/L43.4 pCi/L39.3%First on file

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

Benton County, Geology

The ground under Benton County

Predicted

USGS's geologic map puts all of Benton 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 Benton 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.High1399.9%

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

Benton County beside the ground around it

Benton County has more high-potential ground than Indiana as a whole: 100% of its land against 56.6%. Of the 7 counties that border it, none has as large a share of high-potential ground; Tippecanoe County comes nearest at 100%.

Share of land by USGS radon potential: Benton County, the 7 counties bordering it and Indiana
AreaEPA zoneLow potentialModerate potentialHigh potential
Benton CountyZone 1NoneNone100%
Newton CountyZone 2None50.9%49.1%
White CountyZone 1None0.7%99.3%
Warren CountyZone 1NoneNone100%
Tippecanoe CountyZone 1NoneNone100%
Jasper CountyZone 2None46.0%54.0%
Iroquois County, ILZone 1None32.0%68.0%
Vermilion County, ILZone 1NoneNone100%
Indiana92 counties, pooled by land areaVariesNone43.4%56.6%

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

Local help

Benton County, Local resources

Radon testing and mitigation in Benton 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

Benton County, Questions

Questions about radon in Benton County

Are radon levels high in Benton County?

Over the 2008 to 2017 laboratory totals, 61.8% of the radon tests reported to CDC for Benton County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.7 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 2 reported a higher share; pooled, the state comes to 38.9%.

Which counties border Benton County?

Benton County borders 7 counties: Newton County, IN, White County, IN, Warren County, IN, Tippecanoe County, IN, Jasper County, IN, Iroquois County, IL and Vermilion County, IL.

Products

Benton County, Products

Testing a home in Benton County

In Benton County, 61.8% of 34 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 Benton 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

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

Explore

Benton County, Bordering counties

Counties bordering Benton County

Calculated by Radon411

Benton County, Cities and towns

Cities and towns in Benton County

The Census Bureau estimates 8,883 residents in Benton County for July 1, 2025, 175 more than in 2020 (+2.0%). That works out to 22 people per square mile of land. Its largest town, Fowler, has 2,386 residents, 26.9% of the total. Reported testing is thin here: 34 tests over 2008 to 2017, or 3.8 for every 1,000 residents (2025 estimate), where Indiana as a whole comes to 6.2.

From Fowler to Ambia, CDC publishes no figure by town: each reads Benton County's.

The cities and towns in Benton County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Fowler2,386+2.2%26.9%
Oxford1,183+1.9%13.3%
Otterbeinextends beyond Benton County1,139−0.3%Counted whole
Boswell812+1.8%9.1%
Earl Park369+1.9%4.2%
Ambia231+1.3%2.6%

6 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 Benton County is counted whole, so it has no share.

Benton County, Homes

Homes in Benton County

Benton County is a place of houses on their own lots: 87% of its 3,778 homes are detached single-family houses, against 73% across Indiana. The homes are older than Indiana's as a whole: half were built before 1952 (1976 for Indiana), and 61% date from before 1960. Owners live in 81% of the occupied homes (Indiana: 70%), so for most households a test and a fix are their own to order.

Homes in Benton County, Indiana, 2019 to 2023
HomesBenton CountyIndiana
Housing units3,7782,953,344
Detached houses87%73%
In buildings of 5 or more3%13%
Mobile homes4%4%
Built before 196061%32%
Built since 20009%21%
Middle year built19521976
Owner-occupied81%70%

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