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Radon Levels in Steuben County, Indiana

EPA puts Steuben County in Zone 1, its highest radon zone, and high results are common there: 55.7% of the 140 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

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  • Share at 4+ pCi/L

    55.7%

    16.8 pts above IN

    Steuben
    55.7%
    Indiana
    38.9%

    140 tests, 2008 to 2017

  • Median result

    4.5pCi/L

    Action level reached

    Steuben
    4.5 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    140

    36th of 69 by tests

    Steuben
    140
    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

    10 of 69

    Top quarter

    Steuben
    55.7%
    Miami
    63.3%

    By share, of 69 with 30+ tests

Read a result for Steuben County

Starts at Steuben County's median, 4.5 pCi/L

4.5pCi/L

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

EPA’s reading of 4.5 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. Steuben County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Steuben County, At a glance

Steuben County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

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

Reported results by concentration band, Steuben County, 2008 to 2017, laboratory
Under 2 pCi/L: 25%2 to 4 pCi/L: 19%4 pCi/L and above: 56%

Of 140 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Steuben County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L3525.0%
2 to 4 pCi/L2719.3%
4 pCi/L and above7855.7%
What these figures count

These are the 140 tests reported to CDC for Steuben 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

Steuben County, Compared

Steuben County radon figures, compared

Calculated by Radon411

More than half: 55.7% of the 140 radon tests reported to CDC for Steuben County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 10th of 69 Indiana counties with 30 or more tests for the same period. That is 16.8 points above the 38.9% pooled from 92 Indiana counties.

The median result, 4.5 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 50.5 pCi/L. The rest split 25.0% under 2 pCi/L and 19.3% from 2 to 4 (Indiana: 32.8% and 28.3%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 55.7% share point the same way here.

1 of its 5 bordering counties with figures ran higher, led by DeKalb County at 56.6%; LaGrange County reported 41.7%. 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 Steuben County went from 68 tests (2005 to 2014) to 140 (2008 to 2017), the share going from 52.9% to 55.7%.

Nationally, every county with a figure for the same period pools to 35.7%; Steuben County sits 20.0 points above it. CDC also counts 13 tests taken after mitigation in Steuben County for the same period: tests in homes where a fix was already in.

Steuben County against Indiana, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Steuben County
Steuben County14055.7%4.5 pCi/LThis county
Indiana, pooled92 counties, pooled43,14838.9%Not pooled−16.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−20.0 points
Miami Countyhighest in the state3063.3%5.3 pCi/L+7.6 points
Jasper Countylowest in the state7114.1%1.2 pCi/L−41.6 points
DeKalb County, INborders it24256.6%4.4 pCi/L+0.9 points
Branch County, MIborders it1,04855.4%4.4 pCi/L−0.3 points
Hillsdale County, MIborders it2,08654.8%4.4 pCi/L−0.9 points
Noble County, INborders it13652.9%4.3 pCi/L−2.8 points
Williams County, OHborders it2842.9%3.3 pCi/L−12.8 points
LaGrange County, INborders it12041.7%3.4 pCi/L−14.0 points
Where Steuben County's reported results fell, 2008 to 2017, laboratory, beside Indiana and the United States
ResultSteuben County testsSteuben County shareIndiana shareU.S. shareAgainst Indiana
Under 2 pCi/L3525.0%32.8%39.6%−7.8 points
2 to 4 pCi/L2719.3%28.3%24.7%−9.0 points
4 pCi/L and above7855.7%38.9%35.7%+16.8 points
Steuben 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
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
Fountain County12 of 696055.0%4.6 pCi/L
Noble County13 of 6913652.9%4.3 pCi/L
Whitley County14 of 6918451.6%4.0 pCi/L
Kosciusko County15 of 691,24850.6%4.0 pCi/L
Steuben County ten-year laboratory totals, against Indiana's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIndiana, pooledChange from the row before
2008 to 201714055.7%4.5 pCi/L50.5 pCi/L38.9%+0.1 points
2007 to 201610855.6%4.6 pCi/L23.3 pCi/L39.2%+2.3 points
2006 to 20157553.3%4.3 pCi/L19.6 pCi/L39.6%+0.4 points
2005 to 20146852.9%4.2 pCi/L19.6 pCi/L39.3%First on file

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

Steuben County, Geology

The ground under Steuben County

Predicted

USGS's geologic map puts all of Steuben County's mapped land in one class: high radon potential. The map puts 51.6% of Steuben County in the area it calls Saginaw Lobe and 48.2% in Huron-Erie Lobe. USGS gives the first a radon index of 12 and the second 13, both in the high band (12 to 17).

USGS's geologic areas under Steuben County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Saginaw LobeClayey and loamy glacial deposits.High1251.6%
Huron-Erie LobeCalcareous clayey and loamy glacial deposits derived from marine carbonate and clastic sedimentary rocks.High1348.2%

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

Steuben County beside the ground around it

Steuben 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; Branch County, MI comes nearest at 100%.

Share of land by USGS radon potential: Steuben County, the 6 counties bordering it and Indiana
AreaEPA zoneLow potentialModerate potentialHigh potential
Steuben CountyZone 1NoneNone100%
DeKalb CountyZone 1NoneNone100%
Branch County, MIZone 1NoneNone100%
Williams County, OHZone 2None9.7%90.3%
LaGrange CountyZone 1NoneNone100%
Noble CountyZone 1NoneNone100%
Hillsdale County, MIZone 1NoneNone100%
Indiana92 counties, pooled by land areaVariesNone43.4%56.6%

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

Local help

Steuben County, Local resources

Radon testing and mitigation in Steuben 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

Steuben County, Questions

Questions about radon in Steuben County

Are radon levels high in Steuben County?

Over the 2008 to 2017 laboratory totals, 55.7% of the radon tests reported to CDC for Steuben County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.5 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 9 reported a higher share; pooled, the state comes to 38.9%.

Which counties border Steuben County?

Steuben County borders 6 counties: DeKalb County, IN, Branch County, MI, Williams County, OH, LaGrange County, IN, Noble County, IN and Hillsdale County, MI.

Products

Steuben County, Products

Testing a home in Steuben County

In Steuben County, 55.7% of 140 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 Steuben 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

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

Explore

Steuben County, Bordering counties

Counties bordering Steuben County

Calculated by Radon411

Steuben County, Cities and towns

Cities and towns in Steuben County

The Census Bureau estimates 34,799 residents in Steuben County for July 1, 2025, 347 more than in 2020 (+1.0%). That works out to 113 people per square mile of land. Its largest town, Angola, has 9,366 residents, 26.9% of the total. Reported testing is thin here: 140 tests over 2008 to 2017, or 4.0 for every 1,000 residents (2025 estimate), where Indiana as a whole comes to 6.2.

From Angola to Clear Lake, CDC publishes no figure by town: each reads Steuben County's.

The cities and towns in Steuben County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Angola9,366Level26.9%
Fremont2,058+1.2%5.9%
Hamiltonextends beyond Steuben County1,559+2.1%Counted whole
Ashleyextends beyond Steuben County1,037+1.1%Counted whole
Hudson586+1.9%1.7%
Orland390+0.8%1.1%
Clear Lake358+0.6%1.0%

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 Steuben County is counted whole, so it has no share.

Steuben County, Homes

Homes in Steuben County

Steuben County is a place of houses on their own lots: 77% of its 19,055 homes are detached single-family houses, against 73% across Indiana. Half of its homes were built before 1980, close to Indiana's 1976: 30% date from before 1960 and 21% from 2000 or later. Owners live in 80% of the occupied homes (Indiana: 70%), so for most households a test and a fix are their own to order.

Homes in Steuben County, Indiana, 2019 to 2023
HomesSteuben CountyIndiana
Housing units19,0552,953,344
Detached houses77%73%
In buildings of 5 or more4%13%
Mobile homes13%4%
Built before 196030%32%
Built since 200021%21%
Middle year built19801976
Owner-occupied80%70%

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