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 Alpine County, California
EPA puts Alpine County in Zone 2, its middle radon zone, and only 19 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
Highest bordering
37.0%
Douglas County
- Douglas
- 37.0%
- Calaveras
- 17.6%
5 of 6 neighbours have 30+ tests, 2008 to 2017
Nearest county
23.0%
Tuolumne County, 40 miles
- Tuolumne
- 23.0%
- California
- 10.3%
Share at 4+ pCi/L, 74 tests, 2008 to 2017
Ground above low
100.0%
57.3 pts above California
- Alpine
- 100.0%
- California
- 42.7%
Share of land USGS rates moderate or high potential
Tests reported
19
Too few for a share
- Alpine
- 19
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Read a result for Alpine County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 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.
The data
Alpine County, At a glance
Alpine County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Alpine County is a
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 Alpine County, 2008 to 2017, laboratory
CDC holds 19 reported tests for Alpine County over the 2008 to 2017 laboratory totals, with a median of 4.5 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Alpine County beside the counties around it is how this page reads it.
What these figures count
Only 19 tests were reported to CDC for Alpine 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).
Alpine County, Compared
Alpine County radon figures, compared
Calculated by Radon411CDC's largest figure for Alpine County rests on 19 tests over the 2008 to 2017 laboratory totals, 12 of them at or above 4 pCi/L, so each test moves its share by 5.3 points and no rank or comparison is drawn from it. Results reached as high as 33.0 pCi/L, with a middle value of 4.5 pCi/L.
Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Douglas County, NV reported the largest share at or above 4 pCi/L, 37.0%, and Calaveras County the smallest, 17.6%, with El Dorado County at 30.3%, Amador County at 27.8% and Tuolumne County at 23.0% between. Farther out, Placer County (58 miles away) at 7.4%, Nevada County (70 miles away) at 25.0% and Sacramento County (83 miles away) at 7.7% have figures too. Pooled across 56 California counties, 10.3% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, El Dorado County reported the highest share (30.3%) and Sonoma County the lowest (0.8%). EPA's 1993 map puts Alpine County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Alpine County, Geology
The ground under Alpine County
PredictedUSGS's geologic map puts all of Alpine County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Sierra Nevada, to which USGS gives a radon index of 9, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Sierra Nevada | Northern Sierra Nevada is underlain primarily by Paleozoic and Mesozoic metamorphic rocks. Granitic rocks predominate in the southern Sierrra Nevada , with lesser Mesozoic metamorphic rocks. | Moderate | 9 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Alpine County beside the ground around it
Across California 0.1% of the land is rated high; none of Alpine County's is. Of the 6 counties that border it, none has as large a share of moderate-potential ground; Amador County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Alpine County, Local resources
Radon testing and mitigation in Alpine County
- California Indoor Radon ProgramCalifornia Indoor Radon Program, run by California Department of Public Health, licenses or certifies radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in California.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Discounted test kits can be purchased through our partner laboratory, Alpha Energy, for $14.95.
- Compare kits
- Professionals in California4 professionals are listed in California.
What California's program says
- Phone
- 1-800-745-7236
- Radonprogram@cdph.ca.gov
- Licensing of radon professionals
The Radon Program certifies all radon service providers operating in California.
What it means
Alpine County, Questions
Questions about radon in Alpine County
Are radon levels high in Alpine County?
Over the 2008 to 2017 laboratory totals, 63.2% of the radon tests reported to CDC for Alpine County, California were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.5 pCi/L. Of the counties bordering it, 5 have a figure over the 2008 to 2017 laboratory totals: Douglas County, NV reported the largest share at or above 4 pCi/L, 37.0%, and Calaveras County the smallest, 17.6%, with El Dorado County at 30.3%, Amador County at 27.8% and Tuolumne County at 23.0% between.
Which counties border Alpine County?
Alpine County borders 6 counties: Douglas County, NV, El Dorado County, CA, Tuolumne County, CA, Amador County, CA, Calaveras County, CA and Mono County, CA.
Products
Alpine County, Products
Testing a home in Alpine County
No CDC figure names Alpine County; the nearest county with one, Tuolumne County (40 miles away), reported 23.0% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Alpine 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
Hello Radon C battery radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Alpine County, Bordering counties
Counties bordering Alpine County
Calculated by Radon411- Radon levels in Mono County, CAEPA zone 2
50.0%at or above 4 pCi/L
Median 4.6 pCi/L · 20 tests
- Radon levels in Douglas County, NVEPA zone 1
37.0%at or above 4 pCi/L
Median 3.1 pCi/L · 1,617 tests
- Radon levels in El Dorado County, CAEPA zone 2
30.3%at or above 4 pCi/L
Median 1.6 pCi/L · 274 tests
- Radon levels in Amador County, CAEPA zone 2
27.8%at or above 4 pCi/L
Median 2.3 pCi/L · 36 tests
- Radon levels in Tuolumne County, CAEPA zone 2
23.0%at or above 4 pCi/L
Median 1.4 pCi/L · 74 tests
- Radon levels in Calaveras County, CAEPA zone 2
17.6%at or above 4 pCi/L
Median 1.7 pCi/L · 34 tests
Alpine County, Residents
Who lives in Alpine County
Alpine County has been losing residents: from 1,180 in 2020 to 1,043 on July 1, 2025, a fall of 11.6% by the Census Bureau's estimates. Spread over its land, that is 1.4 people to the square mile. Testing is reported here more often than across the state: CDC's 19 reported tests for 2008 to 2017 come to 18.2 for every 1,000 residents (2025 estimate), against 0.2 for California.
Census lists no incorporated place in Alpine County: every home in it reads the county's figures.
Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Alpine County, Homes
Homes in Alpine County
Of Alpine County's 1,587 homes, 68% are detached houses, against 57% across California; 23% are in buildings of five or more homes. Half of its homes were built before 1981, close to California's 1976: 12% date from before 1960 and 16% from 2000 or later. Owners live in 81% of the occupied homes (California: 56%), so for most households a test and a fix are their own to order.
| Homes | Alpine County | California |
|---|---|---|
| Housing units | 1,587 | 14,532,683 |
| Detached houses | 68% | 57% |
| In buildings of 5 or more | 23% | 24% |
| Mobile homes | 2% | 4% |
| Built before 1960 | 12% | 27% |
| Built since 2000 | 16% | 18% |
| Middle year built | 1981 | 1976 |
| Owner-occupied | 81% | 56% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.