Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Powell County, Montana
EPA puts Powell County in Zone 1, its highest radon zone, and only 29 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
66.7%
20.1 pts above MT
- Powell
- 66.7%
- Montana
- 46.6%
30 tests, 2007 to 2016
Median result
6.6pCi/L
Action level reached
- Powell
- 6.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2007 to 2016
Tests reported
30
25th of 25 by tests
- Powell
- 30
- Missoula
- 2,365
Reported to CDC before any fix, 2007 to 2016
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Montana
6 of 25
Top quarter
- Powell
- 66.7%
- Sheridan
- 75.7%
By share, of 25 with 30+ tests
Read a result for Powell County
Starts at Powell County's median, 6.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 6.6 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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. Powell County's median reported result, 2007 to 2016.
The data
Powell County, At a glance
Powell County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Powell County in
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 Powell County, 2008 to 2017, laboratory
CDC holds 29 reported tests for Powell County over the 2008 to 2017 laboratory totals, with a median of 4.2 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Powell County beside the counties around it is how this page reads it.
What these figures count
Only 29 tests were reported to CDC for Powell County over 2008 to 2017 (laboratory totals), and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Powell County, Compared
Powell County radon figures, compared
Calculated by Radon411More than half: 66.7% of the 30 radon tests reported to CDC for Powell County over the 2007 to 2016 laboratory totals read at least 4 pCi/L. That places it 6th of 25 Montana counties with 30 or more tests for the same period. That is 20.1 points above the 46.6% pooled from 51 Montana counties.
The newest figure, over the 2008 to 2017 laboratory totals, counts only 29 tests (58.6% at or above 4 pCi/L), too few to compare, so this reading uses the 30-test figure.
The median result, 6.6 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 80.4 pCi/L. The rest split 10.0% under 2 pCi/L and 23.3% from 2 to 4 (Montana: 28.3% and 25.1%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 66.7% share point the same way here.
1 of its 4 bordering counties with figures ran higher, led by Jefferson County at 70.0%; Flathead County reported 38.2%. Statewide for the same period, Sheridan County reported the highest share (75.7%) and Cascade County the lowest (34.5%).
CDC's ten-year totals for Powell County went from 23 tests (2005 to 2014) to 29 (2008 to 2017), the share going from 78.3% to 58.6%.
Nationally, every county with a figure for the same period pools to 35.8%; Powell County sits 30.9 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Powell County, Geology
The ground under Powell County
PredictedUSGS's geologic map puts all of Powell County's mapped land in one class: high radon potential. All of it lies in the area the map calls Northern Rocky Mountains, to which USGS gives a radon index of 13, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Northern Rocky Mountains | Granitic, metaigneous, metasedimentary rocks, valley fill colluvium and alluvium. | High | 13 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Powell County beside the ground around it
Powell County has more high-potential ground than Montana as a whole: 100% of its land against 78.5%. Of the 6 counties that border it, none has as large a share of high-potential ground; Deer Lodge County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Powell County, Local resources
Radon testing and mitigation in Powell County
- Radon Control ProgramRadon Control Program, run by Montana DEQ, does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Montana.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Energy Bureau staff manage the radon information toll-free hotline and distribute subsidized radon test kits to Montana residents.
- Compare kits
- See the Montana directoryNo professionals are listed in Montana yet. The state program can point you to registered testers and mitigators.
What Montana's program says
- Phone
- 1-800-546-0483
- Licensing of radon professionals
Montana DEQ does not certify or require proof of certification for the contractors listed.
What it means
Powell County, Questions
Questions about radon in Powell County
Are radon levels high in Powell County?
Over the 2008 to 2017 laboratory totals, 58.6% of the radon tests reported to CDC for Powell County, Montana were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.2 pCi/L. Of 25 Montana counties with 30 or more tests for the same period, 5 reported a higher share; pooled, the state comes to 46.6%.
Which counties border Powell County?
Powell County borders 6 counties: Lewis and Clark County, Missoula County, Granite County, Deer Lodge County, Jefferson County and Flathead County.
Products
Powell County, Products
Testing a home in Powell County
In Powell County, 66.7% of 30 tests reported to CDC over the 2007 to 2016 laboratory totals reached 4 pCi/L, against 46.6% pooled across Montana. In Zone 1 the year-round level in Powell 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
MonitorAEGTEST
HOUND-1011S rechargeable radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 12 hours
Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Powell County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Powell County
Explore
Powell County, Bordering counties
Counties bordering Powell County
Calculated by Radon411- Radon levels in Jefferson CountyEPA zone 1
70.0%at or above 4 pCi/L
Median 6.3 pCi/L · 60 tests · 3.3 points above Powell County
- Radon levels in Lewis and Clark CountyEPA zone 1
62.0%at or above 4 pCi/L
Median 5.0 pCi/L · 460 tests · 4.7 points below Powell County
- Radon levels in Missoula CountyEPA zone 1
47.2%at or above 4 pCi/L
Median 3.7 pCi/L · 2,365 tests · 19.5 points below Powell County
- Radon levels in Flathead CountyEPA zone 1
38.2%at or above 4 pCi/L
Median 2.9 pCi/L · 921 tests · 28.5 points below Powell County
- Radon levels in Granite CountyEPA zone 1
33.3%at or above 4 pCi/L
Median 1.6 pCi/L · 6 tests · 33.4 points below Powell County
- Radon levels in Deer Lodge CountyEPA zone 1
28.6%at or above 4 pCi/L
Median 2.6 pCi/L · 14 tests · 38.1 points below Powell County
Powell County, Cities and towns
Cities and towns in Powell County
The Census Bureau estimates 7,157 residents in Powell County for July 1, 2025, 216 more than in 2020 (+3.1%). Spread over its land, that is 3.1 people to the square mile. Deer Lodge, its one incorporated place, has 3,025 residents, 42.3% of the total. Reported testing is thin here: 30 tests over 2007 to 2016, or 4.2 for every 1,000 residents (2025 estimate), where Montana as a whole comes to 8.1.
Deer Lodge is the one incorporated place here; CDC publishes no figure by town, so it reads Powell County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Deer Lodge | 3,025 | Level | 42.3% |
One incorporated place, 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).
Powell County, Homes
Homes in Powell County
Powell County is a place of houses on their own lots: 76% of its 2,969 homes are detached single-family houses, against 69% across Montana. The homes are older than Montana's as a whole: half were built before 1965 (1980 for Montana), and 46% date from before 1960. 69% of occupied homes are lived in by their owner (Montana: 69%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Powell County | Montana |
|---|---|---|
| Housing units | 2,969 | 522,939 |
| Detached houses | 76% | 69% |
| In buildings of 5 or more | 3% | 9% |
| Mobile homes | 16% | 10% |
| Built before 1960 | 46% | 26% |
| Built since 2000 | 14% | 27% |
| Middle year built | 1965 | 1980 |
| Owner-occupied | 69% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.