Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Millard County, Utah
EPA puts Millard County in Zone 2, its middle radon zone, and high results are common there: 58.2% of the 55 radon tests reported to CDC (2023) 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
Share at 4+ pCi/L
58.2%
22.1 pts above UT
- Millard
- 58.2%
- Utah
- 36.1%
55 tests, 2023
Median result
4.4pCi/L
Action level reached
- Millard
- 4.4 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
55
18th of 22 by tests
- Millard
- 55
- Salt Lake
- 9,658
Reported to CDC before any fix, 2023
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Utah
5 of 22
Top quarter
- Millard
- 58.2%
- Beaver
- 66.7%
By share, of 22 with 30+ tests
Read a result for Millard County
Starts at Millard County's median, 4.4 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.4 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. Millard County's median reported result, 2023.
The data
Millard County, At a glance
Millard County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Millard County is a
USGS geologic potential: Moderate across 91% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Millard County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 0.0% |
| 2015 | 33.3% |
| 2016 | 50.0% |
| 2017 | 44.4% |
| 2018 | 37.5% |
| 2019 | 0.0% |
| 2020 | 0.0% |
| 2021 | 39.3% |
| 2022 | 26.2% |
| 2023 | 58.2% |
2023: 58.2%. Across these years the share ran from 0.0% to 58.2%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 55 tests reported to CDC for Millard County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Millard County, Compared
Millard County radon figures, compared
Calculated by Radon411More than half: 58.2% of the 55 radon tests reported to CDC for Millard County in 2023 read at least 4 pCi/L. That places it 5th of 22 Utah counties with 30 or more tests for the same period. That is 22.1 points above the 36.1% pooled from 29 Utah counties.
The median result, 4.4 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 19.8 pCi/L. The rest split 14.5% under 2 pCi/L and 27.3% from 2 to 4 (Utah: 35.4% and 28.5%). The reported tests do not follow EPA's Zone 2 label for Millard County (predicted average between 2 and 4 pCi/L): 58.2% of them reached 4 pCi/L, fewer than that label suggests.
3 of its 4 bordering counties with figures ran higher, led by Beaver County at 66.7%; Sevier County reported 57.4%. Statewide for the same period, Beaver County reported the highest share (66.7%) and Washington County the lowest (9.9%).
The busiest year on file was 2022, with 126 tests reported; the quietest, 2014, had 1.
Nationally, every county with a figure for the same period pools to 33.4%; Millard County sits 24.8 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Millard County, Geology
The ground under Millard County
PredictedMost of the ground under Millard County is one class on USGS's geologic map: 90.7% of its land is moderate radon potential, with 9.3% high. The map puts 90.7% of Millard County in the area it calls Basin and Range and 8.6% in Northern High Plateau, with one smaller area beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 12, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Basin and Range | Quaternary sedimentary and igneous rocks. | Moderate | 11 | 90.7% |
| Northern High Plateau | Tertiary and Cretaceous sedimentary rocks. | High | 12 | 8.6% |
| High Plateau | Tertiary volcanic and volcaniclastic rocks. | High | 13 | 0.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Millard County beside the ground around it
Utah as a whole has more high-potential ground than Millard County: 32.8% of its land, against 9.3% here. Every one of the 6 counties that border it has more high-potential ground, Sanpete County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Millard County, Local resources
Radon testing and mitigation in Millard County
- Indoor Radon ProgramIndoor Radon Program, run by Utah Department of Environmental Quality, states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in Utah.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- See the Utah directoryNo professionals are listed in Utah yet. The state program can point you to registered testers and mitigators.
What Utah's program says
- Phone
- (801) 536-0091
- Disclosure when a home is sold or rented
Utah requires that sellers disclose "Hazardous Conditions: Are there any hazardous conditions on the Property such as Radon gas in house or well?"
What it means
Millard County, Questions
Questions about radon in Millard County
Are radon levels high in Millard County?
In 2023, 58.2% of the radon tests reported to CDC for Millard County, Utah were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.4 pCi/L. Of 22 Utah counties with 30 or more tests for the same period, 4 reported a higher share; pooled, the state comes to 36.1%.
Which counties border Millard County?
Millard County borders 6 counties: Juab County, UT, Beaver County, UT, Sevier County, UT, Sanpete County, UT, White Pine County, NV and Lincoln County, NV.
Products
Millard County, Products
Testing a home in Millard County
In Millard County, 58.2% of 55 tests reported to CDC in 2023 reached 4 pCi/L, against 36.1% pooled across Utah. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Millard County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Monitor
Wave Radon battery smart radon monitor
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- App only
Method: Alpha spectrometry
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Millard County, Bordering counties
Counties bordering Millard County
Calculated by Radon411- Radon levels in Beaver County, UTEPA zone 2
66.7%at or above 4 pCi/L
Median 9.3 pCi/L · 42 tests · 8.5 points above Millard County
- Radon levels in Juab County, UTEPA zone 2
63.3%at or above 4 pCi/L
Median 5.0 pCi/L · 49 tests · 5.1 points above Millard County
- Radon levels in Sanpete County, UTEPA zone 1
60.0%at or above 4 pCi/L
Median 4.6 pCi/L · 150 tests · 1.8 points above Millard County
- Radon levels in Sevier County, UTEPA zone 1
57.4%at or above 4 pCi/L
Median 4.9 pCi/L · 101 tests · 0.8 points below Millard County
- Radon levels in White Pine County, NVEPA zone 1
No CDC figure for 2023; its page reads it against its own neighbours.
- Radon levels in Lincoln County, NVEPA zone 1
No CDC figure for 2023; its page reads it against its own neighbours.
Millard County, Cities and towns
Cities and towns in Millard County
Millard County is growing: the Census Bureau puts it at 14,057 residents on July 1, 2025, up 7.7% from 13,053 in 2020. Spread over its land, that is 2.1 people to the square mile. Its largest town, Delta, has 3,868 residents, 27.5% of the total. Together its 10 incorporated places hold 72.6% of those residents; the other 27.4% live outside any of them. Reported testing is thin here: 55 tests over 2023, or 3.9 for every 1,000 residents (2025 estimate), where Utah as a whole comes to 7.7.
From Delta to Lynndyl, CDC publishes no figure by town: each reads Millard County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Delta | 3,868 | +6.3% | 27.5% |
| Fillmore | 2,874 | +9.3% | 20.4% |
| Hinckley | 674 | +9.8% | 4.8% |
| Oak City | 654 | +6.7% | 4.7% |
| Kanosh | 511 | +1.6% | 3.6% |
| Holden | 470 | +2.8% | 3.3% |
| Scipio | 382 | +7.0% | 2.7% |
| Meadow | 362 | +9.4% | 2.6% |
| Leamington | 285 | +8.8% | 2.0% |
| Lynndyl | 130 | +14.0% | 0.9% |
10 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).
Millard County, Homes
Homes in Millard County
Millard County is a place of houses on their own lots: 90% of its 4,990 homes are detached single-family houses, against 67% across Utah. The homes are older than Utah's as a whole: half were built before 1974 (1991 for Utah), and 37% date from before 1960. Owners live in 78% of the occupied homes (Utah: 71%), so for most households a test and a fix are their own to order.
| Homes | Millard County | Utah |
|---|---|---|
| Housing units | 4,990 | 1,193,082 |
| Detached houses | 90% | 67% |
| In buildings of 5 or more | 3% | 16% |
| Mobile homes | 5% | 3% |
| Built before 1960 | 37% | 16% |
| Built since 2000 | 15% | 37% |
| Middle year built | 1974 | 1991 |
| Owner-occupied | 78% | 71% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.