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Radon Levels in Montgomery County, Indiana

EPA puts Montgomery County in Zone 1, its highest radon zone, and high results are common there: 41.4% of the 152 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

    41.4%

    2.5 pts above IN

    Montgomery
    41.4%
    Indiana
    38.9%

    152 tests, 2008 to 2017

  • Median result

    2.9pCi/L

    Below action level

    Montgomery
    2.9 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    152

    34th of 69 by tests

    Montgomery
    152
    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

    41 of 69

    Middle half

    Montgomery
    41.4%
    Miami
    63.3%

    By share, of 69 with 30+ tests

Read a result for Montgomery County

Starts at Montgomery County's median, 2.9 pCi/L

2.9pCi/L

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

EPA’s reading of 2.9 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. Montgomery County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Montgomery County, At a glance

Montgomery County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Montgomery 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 94% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Montgomery County, 2008 to 2017, laboratory

Reported results by concentration band, Montgomery County, 2008 to 2017, laboratory
Under 2 pCi/L: 33%2 to 4 pCi/L: 26%4 pCi/L and above: 41%

Of 152 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Montgomery County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L5032.9%
2 to 4 pCi/L3925.7%
4 pCi/L and above6341.4%
What these figures count

These are the 152 tests reported to CDC for Montgomery 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

Montgomery County, Compared

Montgomery County radon figures, compared

Calculated by Radon411

In Montgomery County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (63 of 152) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 5.7 points higher. Across 92 Indiana counties pooled together, 38.9% of tests reached that level, so Montgomery County runs 2.5 points above its state.

Of 6 neighbours with a figure, 3 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 34.5% (Putnam County) to 55.0% (Fountain County). By share, Montgomery County is 41st of 69 Indiana counties with 30 or more tests for the same period.

Half the tests came in under 2.9 pCi/L and half over it; the single highest reached 55.5 pCi/L. Below the action level, 50 tests (32.9%) came in under 2 pCi/L, against 32.8% statewide, and 39 tests (25.7%) fell between 2 and 4, against 28.3% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 41.4% share point the same way here. USGS geology rates 94% of the county's land high radon potential. CDC also counts 11 tests taken after mitigation in Montgomery County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Montgomery County went from 113 tests (2005 to 2014) to 152 (2008 to 2017), the share going from 53.1% to 41.4%.

Montgomery County against Indiana, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Montgomery County
Montgomery County15241.4%2.9 pCi/LThis county
Indiana, pooled92 counties, pooled43,14838.9%Not pooled−2.5 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−5.7 points
Miami Countyhighest in the state3063.3%5.3 pCi/L+21.9 points
Jasper Countylowest in the state7114.1%1.2 pCi/L−27.3 points
Parke County, INborders it2568.0%4.8 pCi/L+26.6 points
Fountain County, INborders it6055.0%4.6 pCi/L+13.6 points
Clinton County, INborders it8545.9%3.5 pCi/L+4.5 points
Hendricks County, INborders it1,17041.5%3.2 pCi/L+0.1 points
Boone County, INborders it61439.7%3.0 pCi/L−1.7 points
Tippecanoe County, INborders it1,21836.8%2.7 pCi/L−4.6 points
Putnam County, INborders it11934.5%2.7 pCi/L−6.9 points
Where Montgomery County's reported results fell, 2008 to 2017, laboratory, beside Indiana and the United States
ResultMontgomery County testsMontgomery County shareIndiana shareU.S. shareAgainst Indiana
Under 2 pCi/L5032.9%32.8%39.6%+0.1 points
2 to 4 pCi/L3925.7%28.3%24.7%−2.6 points
4 pCi/L and above6341.4%38.9%35.7%+2.5 points
Montgomery 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
Floyd County36 of 6931642.4%3.3 pCi/L
Washington County37 of 693842.1%3.5 pCi/L
Allen County38 of 693,99041.8%3.3 pCi/L
LaGrange County39 of 6912041.7%3.4 pCi/L
Hendricks County40 of 691,17041.5%3.2 pCi/L
Montgomery County41 of 6915241.4%2.9 pCi/L
Marion County42 of 693,66840.1%3.1 pCi/L
Boone County43 of 6961439.7%3.0 pCi/L
Marshall County44 of 6938339.7%3.2 pCi/L
Johnson County45 of 6955639.4%2.9 pCi/L
Owen County46 of 6911039.1%2.8 pCi/L
Montgomery County ten-year laboratory totals, against Indiana's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIndiana, pooledChange from the row before
2008 to 201715241.4%2.9 pCi/L55.5 pCi/L38.9%−1.5 points
2007 to 201616142.9%3.2 pCi/L55.5 pCi/L39.2%−10.4 points
2006 to 201512253.3%4.5 pCi/L30.7 pCi/L39.6%+0.2 points
2005 to 201411353.1%4.6 pCi/L30.7 pCi/L39.3%First on file

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

Montgomery County, Geology

The ground under Montgomery County

Predicted

Most of the ground under Montgomery County is one class on USGS's geologic map: 94.1% of its land is high radon potential, with 5.9% moderate. The map puts 94.1% of Montgomery County in the area it calls Huron-Erie Lobe and 5.9% in Wabash Lowland. USGS gives the first a radon index of 13, in the high band (12 to 17), and the second 10, in the moderate band (9 to 11).

USGS's geologic areas under Montgomery 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.High1394.1%
Wabash LowlandLoess, pre-Wisconsinan glacial deposits, Pennsylvanian shale, sandstone, and carbonate bedrock.Moderate105.9%

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

Montgomery County beside the ground around it

Montgomery County has more high-potential ground than Indiana as a whole: 94.1% of its land against 56.6%. Of the 7 counties that border it, 5 have more high-potential ground, Boone County the most at 100%.

Share of land by USGS radon potential: Montgomery County, the 7 counties bordering it and Indiana
AreaEPA zoneLow potentialModerate potentialHigh potential
Montgomery CountyZone 1None5.9%94.1%
Fountain CountyZone 1None5.0%95.0%
Putnam CountyZone 1None30.0%70.0%
Boone CountyZone 1NoneNone100%
Tippecanoe CountyZone 1NoneNone100%
Parke CountyZone 2None72.8%27.2%
Clinton CountyZone 1NoneNone100%
Hendricks CountyZone 1NoneNone100%
Indiana92 counties, pooled by land areaVariesNone43.4%56.6%

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

Local help

Montgomery County, Local resources

Radon testing and mitigation in Montgomery 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

Montgomery County, Questions

Questions about radon in Montgomery County

Are radon levels high in Montgomery County?

Over the 2008 to 2017 laboratory totals, 41.4% of the radon tests reported to CDC for Montgomery County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.9 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 40 reported a higher share; pooled, the state comes to 38.9%.

Which counties border Montgomery County?

Montgomery County borders 7 counties: Fountain County, Putnam County, Boone County, Tippecanoe County, Parke County, Clinton County and Hendricks County.

Products

Montgomery County, Products

Testing a home in Montgomery County

In Montgomery County, 41.4% of 152 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 Montgomery 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

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

Explore

Montgomery County, Bordering counties

Counties bordering Montgomery County

Calculated by Radon411

Montgomery County, Cities and towns

Cities and towns in Montgomery County

The Census Bureau estimates 38,954 residents in Montgomery County for July 1, 2025, 1,016 more than in 2020 (+2.7%). That works out to 77 people per square mile of land. Its largest town, Crawfordsville, has 16,699 residents, 42.9% of the total. Together its 11 incorporated places hold 57.0% of those residents; the other 43.0% live outside any of them. Reported testing is thin here: 152 tests over 2008 to 2017, or 3.9 for every 1,000 residents (2025 estimate), where Indiana as a whole comes to 6.2.

From Crawfordsville to Alamo, CDC publishes no figure by town: each reads Montgomery County's.

The cities and towns in Montgomery County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Crawfordsville16,699+2.2%42.9%
Ladoga1,103+2.5%2.8%
Waynetown976+2.8%2.5%
Linden742+2.8%1.9%
Darlington724+2.5%1.9%
New Market567+2.5%1.5%
Waveland443+2.3%1.1%
New Richmond318+2.6%0.8%
New Ross314+1.9%0.8%
Wingate252+2.9%0.6%
Alamo67+4.7%0.2%

11 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).

Montgomery County, Homes

Homes in Montgomery County

Montgomery County is a place of houses on their own lots: 77% of its 16,534 homes are detached single-family houses, against 73% across Indiana. The homes are older than Indiana's as a whole: half were built before 1965 (1976 for Indiana), and 43% date from before 1960. Owners live in 78% of the occupied homes (Indiana: 70%), so for most households a test and a fix are their own to order.

Homes in Montgomery County, Indiana, 2019 to 2023
HomesMontgomery CountyIndiana
Housing units16,5342,953,344
Detached houses77%73%
In buildings of 5 or more8%13%
Mobile homes6%4%
Built before 196043%32%
Built since 200014%21%
Middle year built19651976
Owner-occupied78%70%

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