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Radon Levels in Bannock County, Idaho

EPA puts Bannock County in Zone 2, its middle radon zone, and high results are common there: 41.9% of the 732 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

    41.9%

    0.4 pts above ID

    Bannock
    41.9%
    Idaho
    41.5%

    732 tests, 2008 to 2017

  • Median result

    3.2pCi/L

    Below action level

    Bannock
    3.2 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    732

    4th of 37 by tests

    Bannock
    732
    Ada
    3,030

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Idaho

    16 of 37

    Middle half

    Bannock
    41.9%
    Bear Lake
    78.1%

    By share, of 37 with 30+ tests

Read a result for Bannock County

Starts at Bannock County's median, 3.2 pCi/L

3.2pCi/L

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

EPA’s reading of 3.2 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. Bannock County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Bannock County, At a glance

Bannock County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Bannock County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Bannock County, 2008 to 2017, laboratory
Under 2 pCi/L: 27%2 to 4 pCi/L: 31%4 pCi/L and above: 42%

Of 732 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Bannock County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L19927.2%
2 to 4 pCi/L22630.9%
4 pCi/L and above30741.9%
What these figures count

These are the 732 tests reported to CDC for Bannock 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

Bannock County, Compared

Bannock County radon figures, compared

Calculated by Radon411

In Bannock County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (307 of 732) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 6.2 points higher. Across 44 Idaho counties pooled together, 41.5% of tests reached that level, so Bannock County runs 0.4 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 26.8% (Power County) to 52.0% (Bingham County). By share, Bannock County is 16th of 37 Idaho counties with 30 or more tests for the same period.

Half the tests came in under 3.2 pCi/L and half over it; the single highest reached 78.4 pCi/L. Below the action level, 199 tests (27.2%) came in under 2 pCi/L, against 31.5% statewide, and 226 tests (30.9%) fell between 2 and 4, against 26.9% statewide.

Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 41.9% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 34 tests taken after mitigation in Bannock County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Bannock County went from 635 tests (2005 to 2014) to 732 (2008 to 2017), the share going from 38.7% to 41.9%.

Bannock County against Idaho, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Bannock County
Bannock County73241.9%3.2 pCi/LThis county
Idaho, pooled44 counties, pooled12,96141.5%Not pooled−0.4 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−6.2 points
Bear Lake Countyhighest in the state3278.1%7.8 pCi/L+36.2 points
Payette Countylowest in the state614.9%1.5 pCi/L−37.0 points
Oneida County, IDborders it2774.1%6.5 pCi/L+32.2 points
Bingham County, IDborders it44652.0%4.2 pCi/L+10.1 points
Caribou County, IDborders it5743.9%3.4 pCi/L+2.0 points
Franklin County, IDborders it7534.7%3.1 pCi/L−7.2 points
Power County, IDborders it4126.8%2.5 pCi/L−15.1 points
Where Bannock County's reported results fell, 2008 to 2017, laboratory, beside Idaho and the United States
ResultBannock County testsBannock County shareIdaho shareU.S. shareAgainst Idaho
Under 2 pCi/L19927.2%31.5%39.6%−4.3 points
2 to 4 pCi/L22630.9%26.9%24.7%+4.0 points
4 pCi/L and above30741.9%41.5%35.7%+0.4 points
Bannock County ranked among the 37 Idaho counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Bingham County11 of 3744652.0%4.2 pCi/L
Adams County12 of 373151.6%4.0 pCi/L
Fremont County13 of 3710149.5%3.9 pCi/L
Elmore County14 of 3715848.1%3.8 pCi/L
Caribou County15 of 375743.9%3.4 pCi/L
Bannock County16 of 3773241.9%3.2 pCi/L
Bonneville County17 of 371,11740.1%3.4 pCi/L
Idaho County18 of 379040.0%2.9 pCi/L
Franklin County19 of 377534.7%3.1 pCi/L
Bonner County20 of 3732133.0%2.3 pCi/L
Clearwater County21 of 373330.3%1.8 pCi/L
Bannock County ten-year laboratory totals, against Idaho's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIdaho, pooledChange from the row before
2008 to 201773241.9%3.2 pCi/L78.4 pCi/L41.5%+0.2 points
2007 to 201672641.7%3.1 pCi/L78.4 pCi/L40.8%+1.6 points
2006 to 201568140.1%3.1 pCi/L78.4 pCi/L41.3%+1.4 points
2005 to 201463538.7%3.0 pCi/L78.4 pCi/L41.1%First on file

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

Bannock County, Geology

The ground under Bannock County

Predicted

USGS's geologic map puts all of Bannock County's mapped land in one class: moderate radon potential. The map puts 91.6% of Bannock County in the area it calls Basin and Range and 8.4% in Eastern Snake river plain and Malheur-Boise-King Section. USGS gives the first a radon index of 11 and the second 10, both in the moderate band (9 to 11).

USGS's geologic areas under Bannock County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Basin and RangeCenozoic to Paleozoic sedimentary rocks.Moderate1191.6%
Eastern Snake river plain and Malheur-Boise-King SectionBasalt flows.Moderate108.4%

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

Bannock County beside the ground around it

Across Idaho 50.7% of the land is rated high; none of Bannock County's is. Of the 5 counties that border it, 2 have more high-potential ground, Franklin County the most at 31.6%.

Share of land by USGS radon potential: Bannock County, the 5 counties bordering it and Idaho
AreaEPA zoneLow potentialModerate potentialHigh potential
Bannock CountyZone 2None100%None
Caribou CountyZone 2None100%None
Oneida CountyZone 2None99.6%0.4%
Power CountyZone 2None100%None
Franklin CountyZone 2None68.4%31.6%
Bingham CountyZone 2None100%None
Idaho44 counties, pooled by land areaVaries8.0%41.3%50.7%

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

Local help

Bannock County, Local resources

Radon testing and mitigation in Bannock County

What Idaho's program says
Phone
800-445-8647
Email
radon@dhw.idaho.gov

What it means

Bannock County, Questions

Questions about radon in Bannock County

Are radon levels high in Bannock County?

Over the 2008 to 2017 laboratory totals, 41.9% of the radon tests reported to CDC for Bannock County, Idaho were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.2 pCi/L. Of 37 Idaho counties with 30 or more tests for the same period, 15 reported a higher share; pooled, the state comes to 41.5%.

Which counties border Bannock County?

Bannock County borders 5 counties: Caribou County, Oneida County, Power County, Franklin County and Bingham County.

Products

Bannock County, Products

Testing a home in Bannock County

In Bannock County, 41.9% of 732 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 41.5% pooled across Idaho. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Bannock County; a long-term test tells the year-round average.

Test kits and monitors3

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Best radon monitors for Bannock County homes, compared

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Bannock County, Bordering counties

Counties bordering Bannock County

Calculated by Radon411

Bannock County, Cities and towns

Cities and towns in Bannock County

The Census Bureau estimates 91,591 residents in Bannock County for July 1, 2025, 4,297 more than in 2020 (+4.9%). That works out to 82 people per square mile of land. Pocatello, the largest place on its list (58,771 residents in all), extends beyond Bannock County, so no share of the total is worked out for it. CDC's 732 reported tests for 2008 to 2017 work out to 8.0 per 1,000 residents (2025 estimate), close to Idaho's 6.4.

From Pocatello to Arimo, CDC publishes no figure by town: each reads Bannock County's.

The cities and towns in Bannock County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Pocatelloextends beyond Bannock County58,771+3.4%Counted whole
Chubbuck16,823+7.3%18.4%
Inkom862+7.3%0.9%
McCammon828+0.1%0.9%
Downey583+3.2%0.6%
Lava Hot Springs374+4.2%0.4%
Arimo362+2.3%0.4%

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

Bannock County, Homes

Homes in Bannock County

Of Bannock County's 35,683 homes, 67% are detached houses, against 74% across Idaho; 9% are in buildings of five or more homes. The homes are older than Idaho's as a whole: half were built before 1975 (1990 for Idaho), and 29% date from before 1960. 69% of occupied homes are lived in by their owner (Idaho: 72%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Bannock County, Idaho, 2019 to 2023
HomesBannock CountyIdaho
Housing units35,683776,683
Detached houses67%74%
In buildings of 5 or more9%9%
Mobile homes8%7%
Built before 196029%18%
Built since 200020%35%
Middle year built19751990
Owner-occupied69%72%

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