Skip to content
RADON411

Locations and reports

Radon Levels in Cass County, Indiana

EPA puts Cass County in Zone 1, its highest radon zone, and 34.1% of its 91 reported radon tests (2008 to 2017, laboratory totals) were 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

    34.1%

    4.8 pts below IN

    Cass
    34.1%
    Indiana
    38.9%

    91 tests, 2008 to 2017

  • Median result

    2.6pCi/L

    Below action level

    Cass
    2.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    91

    48th of 69 by tests

    Cass
    91
    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

    57 of 69

    Lowest quarter

    Cass
    34.1%
    Miami
    63.3%

    By share, of 69 with 30+ tests

Read a result for Cass County

Starts at Cass County's median, 2.6 pCi/L

2.6pCi/L

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

EPA’s reading of 2.6 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. Cass County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Cass County, At a glance

Cass County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

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

Reported results by concentration band, Cass County, 2008 to 2017, laboratory
Under 2 pCi/L: 36%2 to 4 pCi/L: 30%4 pCi/L and above: 34%

Of 91 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Cass County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L3336.3%
2 to 4 pCi/L2729.7%
4 pCi/L and above3134.1%
What these figures count

These are the 91 tests reported to CDC for Cass 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

Cass County, Compared

Cass County radon figures, compared

Calculated by Radon411

In Cass County, about 3 in 10 reported tests over the 2008 to 2017 laboratory totals (31 of 91) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 1.6 points lower. Across 92 Indiana counties pooled together, 38.9% of tests reached that level, so Cass County runs 4.8 points below its state.

Of 5 neighbours with a figure, all 5 reported a larger share at or above 4 pCi/L; the spread is 35.7% (White County) to 63.3% (Miami County). By share, Cass County is 57th of 69 Indiana counties with 30 or more tests for the same period.

Half the tests came in under 2.6 pCi/L and half over it; the single highest reached 73.0 pCi/L. Below the action level, 33 tests (36.3%) came in under 2 pCi/L, against 32.8% statewide, and 27 tests (29.7%) fell between 2 and 4, against 28.3% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 34.1% share point the same way here. USGS geology rates 100% of the county's land high radon potential. CDC also counts 11 tests taken after mitigation in Cass County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Cass County went from 54 tests (2005 to 2014) to 91 (2008 to 2017), the share going from 42.6% to 34.1%.

Cass County against Indiana, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Cass County
Cass County9134.1%2.6 pCi/LThis county
Indiana, pooled92 counties, pooled43,14838.9%Not pooled+4.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+1.6 points
Harrison Countyhighest in the state22162.4%5.5 pCi/L+28.3 points
Jasper Countylowest in the state7114.1%1.2 pCi/L−20.0 points
Miami County, INborders it3063.3%5.3 pCi/L+29.2 points
Carroll County, INborders it3860.5%5.8 pCi/L+26.4 points
Howard County, INborders it21649.1%3.8 pCi/L+15.0 points
Fulton County, INborders it9746.4%3.3 pCi/L+12.3 points
White County, INborders it4235.7%2.7 pCi/L+1.6 points
Pulaski County, INborders it2231.8%2.3 pCi/L−2.3 points
Where Cass County's reported results fell, 2008 to 2017, laboratory, beside Indiana and the United States
ResultCass County testsCass County shareIndiana shareU.S. shareAgainst Indiana
Under 2 pCi/L3336.3%32.8%39.6%+3.5 points
2 to 4 pCi/L2729.7%28.3%24.7%+1.4 points
4 pCi/L and above3134.1%38.9%35.7%−4.8 points
Cass 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
Ripley County52 of 696835.3%2.9 pCi/L
Jennings County53 of 695735.1%2.8 pCi/L
Daviess County54 of 695834.5%3.1 pCi/L
Putnam County55 of 6911934.5%2.7 pCi/L
Monroe County56 of 692,37534.2%2.8 pCi/L
Cass County57 of 699134.1%2.6 pCi/L
Hancock County58 of 6927133.9%2.6 pCi/L
Decatur County59 of 696333.3%2.8 pCi/L
Greene County60 of 694932.7%3.0 pCi/L
Dearborn County61 of 6913630.1%2.6 pCi/L
St. Joseph County62 of 697,34629.3%2.7 pCi/L
Cass County ten-year laboratory totals, against Indiana's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIndiana, pooledChange from the row before
2008 to 20179134.1%2.6 pCi/L73.0 pCi/L38.9%+1.7 points
2007 to 20167132.4%2.5 pCi/L73.0 pCi/L39.2%−5.1 points
2006 to 20156437.5%2.8 pCi/L73.0 pCi/L39.6%−5.1 points
2005 to 20145442.6%3.2 pCi/L73.0 pCi/L39.3%First on file

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

Cass County, Geology

The ground under Cass County

Predicted

USGS's geologic map puts all of Cass County's mapped land in one class: high radon potential. The map puts 71.8% of Cass County in the area it calls Huron-Erie Lobe and 28.2% in Saginaw Lobe. USGS gives the first a radon index of 13 and the second 12, both in the high band (12 to 17).

USGS's geologic areas under Cass 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.High1371.8%
Saginaw LobeClayey and loamy glacial deposits.High1228.2%

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

Cass County beside the ground around it

Cass 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; Carroll County comes nearest at 100%.

Share of land by USGS radon potential: Cass County, the 6 counties bordering it and Indiana
AreaEPA zoneLow potentialModerate potentialHigh potential
Cass CountyZone 1NoneNone100%
Fulton CountyZone 1NoneNone100%
Miami CountyZone 1NoneNone100%
Carroll CountyZone 1NoneNone100%
Pulaski CountyZone 2None56.9%43.1%
White CountyZone 1None0.7%99.3%
Howard CountyZone 1NoneNone100%
Indiana92 counties, pooled by land areaVariesNone43.4%56.6%

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

Local help

Cass County, Local resources

Radon testing and mitigation in Cass 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

Cass County, Questions

Questions about radon in Cass County

Are radon levels high in Cass County?

Over the 2008 to 2017 laboratory totals, 34.1% of the radon tests reported to CDC for Cass County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.6 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 56 reported a higher share; pooled, the state comes to 38.9%.

Which counties border Cass County?

Cass County borders 6 counties: Fulton County, Miami County, Carroll County, Pulaski County, White County and Howard County.

Products

Cass County, Products

Testing a home in Cass County

In Cass County, 34.1% of 91 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 Cass 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

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

Explore

Cass County, Bordering counties

Counties bordering Cass County

Calculated by Radon411

Cass County, Cities and towns

Cities and towns in Cass County

Cass County's population has barely moved since 2020: 37,836 residents on July 1, 2025 against 37,794 then, by the Census Bureau's estimates. That works out to 92 people per square mile of land. Its largest town, Logansport, has 18,287 residents, 48.3% of the total. Together its 5 incorporated places hold 56.7% of those residents; the other 43.3% live outside any of them. Reported testing is thin here: 91 tests over 2008 to 2017, or 2.4 for every 1,000 residents (2025 estimate), where Indiana as a whole comes to 6.2.

From Logansport to Onward, CDC publishes no figure by town: each reads Cass County's.

The cities and towns in Cass County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Logansport18,287−0.3%48.3%
Galveston1,273−0.4%3.4%
Walton1,024+6.2%2.7%
Royal Center794−0.5%2.1%
Onward76Level0.2%

5 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).

Cass County, Homes

Homes in Cass County

Cass County is a place of houses on their own lots: 82% of its 16,389 homes are detached single-family houses, against 73% across Indiana. The homes are older than Indiana's as a whole: half were built before 1955 (1976 for Indiana), and 56% date from before 1960. Owners live in 75% of the occupied homes (Indiana: 70%), so for most households a test and a fix are their own to order.

Homes in Cass County, Indiana, 2019 to 2023
HomesCass CountyIndiana
Housing units16,3892,953,344
Detached houses82%73%
In buildings of 5 or more5%13%
Mobile homes5%4%
Built before 196056%32%
Built since 20006%21%
Middle year built19551976
Owner-occupied75%70%

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