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 Salt Lake County, Utah
EPA puts Salt Lake County in Zone 2, its middle radon zone, and 33.1% of its 9,658 reported radon tests (2023) 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
Share at 4+ pCi/L
33.1%
3.0 pts below UT
- Salt Lake
- 33.1%
- Utah
- 36.1%
9,658 tests, 2023
Median result
2.6pCi/L
Below action level
- Salt Lake
- 2.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
9,658
Most tested in Utah
- 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
15 of 22
Middle half
- Salt Lake
- 33.1%
- Beaver
- 66.7%
By share, of 22 with 30+ tests
Read a result for Salt Lake County
Starts at Salt Lake County's median, 2.6 pCi/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
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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. Salt Lake County's median reported result, 2023.
The data
Salt Lake County, At a glance
Salt Lake County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Salt Lake County is a
USGS geologic potential: Moderate across 68% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Salt Lake County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 40.3% |
| 2015 | 39.4% |
| 2016 | 35.5% |
| 2017 | 37.0% |
| 2018 | 35.6% |
| 2019 | 33.8% |
| 2020 | 34.7% |
| 2021 | 35.4% |
| 2022 | 34.4% |
| 2023 | 33.1% |
2023: 33.1%. Across these years the share ran from 33.1% to 40.3%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 9,658 tests reported to CDC for Salt Lake 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).
Salt Lake County, Compared
Salt Lake County radon figures, compared
Calculated by Radon411In Salt Lake County, about 3 in 10 reported tests in 2023 (3,192 of 9,658) were at or above EPA's action level. Against the national pool of 33.4%, the gap is 0.3 points lower. Across 29 Utah counties pooled together, 36.1% of tests reached that level, so Salt Lake County runs 3.0 points below its state.
Of 6 neighbours with a figure, 4 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 28.4% (Davis County) to 59.4% (Morgan County). By share, Salt Lake County is 15th of 22 Utah counties with 30 or more tests for the same period.
Year by year, 2014 opened at 40.3% and 2023 closed at 33.1% (down 7.2 points), with 2014 the high at 40.3%. Half the tests came in under 2.6 pCi/L and half over it; the single highest reached 480.0 pCi/L. Below the action level, 3,602 tests (37.3%) came in under 2 pCi/L, against 35.4% statewide, and 2,864 tests (29.7%) fell between 2 and 4, against 28.5% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 33.1% share point the same way here. USGS geology rates 68% of the county's land moderate radon potential. CDC also counts 1,462 tests taken after mitigation in Salt Lake County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2022, with 15,201 tests reported; the quietest, 2019, had 994.
Salt Lake CountyUtah, pooled
| Year | Tests | Salt Lake County, at or above 4 pCi/L | Utah, pooled |
|---|---|---|---|
| 2014 | 1,504 | 40.3% | 43.4% |
| 2015 | 2,794 | 39.4% | 42.3% |
| 2016 | 4,546 | 35.5% | 39.8% |
| 2017 | 2,787 | 37.0% | 38.2% |
| 2018 | 1,860 | 35.6% | 36.6% |
| 2019 | 994 | 33.8% | 37.7% |
| 2020 | 1,709 | 34.7% | 37.6% |
| 2021 | 2,148 | 35.4% | 34.2% |
| 2022 | 15,201 | 34.4% | 37.7% |
| 2023 | 9,658 | 33.1% | 36.1% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Salt Lake County, Geology
The ground under Salt Lake County
PredictedUSGS's geologic map splits Salt Lake County: 68.3% of its land is moderate radon potential and 31.7% high. The map puts 67.9% of Salt Lake County in the area it calls Basin and Range and 31.7% in Wasatch Range. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 14, 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 | 67.9% |
| Wasatch Range | Precambrian granite and gneiss and Tertiary igneous rocks that have relatively low uranium concentrations. | High | 14 | 31.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Salt Lake County beside the ground around it
On high-potential ground Salt Lake County is close to Utah as a whole: 31.7% of its land against 32.8%. Of the 6 counties that border it, 4 have more high-potential ground, Morgan County the most at 99.7%.
The map rates the ground, not the air in any home.
Local help
Salt Lake County, Local resources
Radon testing and mitigation in Salt Lake 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
Salt Lake County, Questions
Questions about radon in Salt Lake County
Are radon levels high in Salt Lake County?
In 2023, 33.1% of the radon tests reported to CDC for Salt Lake County, Utah were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.6 pCi/L. Of 22 Utah counties with 30 or more tests for the same period, 14 reported a higher share; pooled, the state comes to 36.1%.
Which counties border Salt Lake County?
Salt Lake County borders 6 counties: Davis County, Morgan County, Utah County, Wasatch County, Summit County and Tooele County.
Products
Salt Lake County, Products
Testing a home in Salt Lake County
In Salt Lake County, 33.1% of 9,658 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 Salt Lake 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
Salt Lake County, Bordering counties
Counties bordering Salt Lake County
Calculated by Radon411- Radon levels in Morgan CountyEPA zone 2
59.4%at or above 4 pCi/L
Median 5.0 pCi/L · 207 tests · 26.3 points above Salt Lake County
- Radon levels in Wasatch CountyEPA zone 2
51.9%at or above 4 pCi/L
Median 4.2 pCi/L · 324 tests · 18.8 points above Salt Lake County
- Radon levels in Tooele CountyEPA zone 2
51.0%at or above 4 pCi/L
Median 4.1 pCi/L · 573 tests · 17.9 points above Salt Lake County
- Radon levels in Utah CountyEPA zone 2
40.6%at or above 4 pCi/L
Median 3.2 pCi/L · 7,833 tests · 7.5 points above Salt Lake County
- Radon levels in Summit CountyEPA zone 2
32.6%at or above 4 pCi/L
Median 2.4 pCi/L · 417 tests · 0.5 points below Salt Lake County
- Radon levels in Davis CountyEPA zone 2
28.4%at or above 4 pCi/L
Median 2.4 pCi/L · 3,594 tests · 4.7 points below Salt Lake County
Salt Lake County, Cities and towns
Cities and towns in Salt Lake County
The Census Bureau estimates 1,220,916 residents in Salt Lake County for July 1, 2025, 33,907 more than in 2020 (+2.9%). Packed into its land, that is 1,645 people per square mile. No town dominates: Salt Lake City, the largest, has 218,428 residents, 17.9% of the total. CDC's 9,658 reported tests for 2023 work out to 7.9 per 1,000 residents (2025 estimate), close to Utah's 7.7.
From Salt Lake City to Alta, CDC publishes no figure by town: each reads Salt Lake County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Salt Lake City | 218,428 | +8.8% | 17.9% |
| West Valley City | 137,491 | −1.8% | 11.3% |
| West Jordan | 116,812 | −0.2% | 9.6% |
| Sandy | 92,386 | −4.9% | 7.6% |
| South Jordan | 87,614 | +12.4% | 7.2% |
| Millcreek | 63,926 | +0.4% | 5.2% |
| Herriman | 63,282 | +12.6% | 5.2% |
| Taylorsville | 57,484 | −4.8% | 4.7% |
| Murray | 53,297 | +5.3% | 4.4% |
| Draperextends beyond Salt Lake County | 50,652 | −0.8% | Counted whole |
| Riverton | 47,395 | +4.6% | 3.9% |
| Midvale | 36,099 | −0.1% | 3.0% |
Places in Salt Lake County with a city page: 1 of 1
- Kearns metro township
- Magna metro township
- Cottonwood Heights
- Holladay
- South Salt Lake
- Bluffdale (part)
- White City metro township
- Emigration Canyon metro township
- Copperton metro township
- Brighton
- Alta
23 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Salt Lake County is counted whole, so it has no share.
Salt Lake County, Homes
Homes in Salt Lake County
Of Salt Lake County's 440,166 homes, 61% are detached houses, against 67% across Utah; 23% are in buildings of five or more homes. Half of its homes were built before 1985, close to Utah's 1991: 19% date from before 1960 and 30% from 2000 or later. 67% of occupied homes are lived in by their owner (Utah: 71%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Salt Lake County | Utah |
|---|---|---|
| Housing units | 440,166 | 1,193,082 |
| Detached houses | 61% | 67% |
| In buildings of 5 or more | 23% | 16% |
| Mobile homes | 2% | 3% |
| Built before 1960 | 19% | 16% |
| Built since 2000 | 30% | 37% |
| Middle year built | 1985 | 1991 |
| Owner-occupied | 67% | 71% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.