Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Adams County, Washington
EPA puts Adams County in Zone 2, its middle radon zone, and only 2 radon tests from it are on file with CDC (2020). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
22.4%
Whitman County
- Whitman
- 22.4%
1 of 4 neighbours have 30+ tests, 2008 to 2017
Nearest county
22.4%
Whitman County, 49 miles
- Whitman
- 22.4%
- Washington
- 25.5%
Share at 4+ pCi/L, 58 tests, 2008 to 2017
Ground above low
100.0%
47.3 pts above Washington
- Adams
- 100.0%
- Washington
- 52.7%
Share of land USGS rates moderate or high potential
Tests reported
7
Too few for a share
- Adams
- 7
- 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 Adams 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
Adams County, At a glance
Adams County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Adams 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 Adams County, 2020
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 0.0% |
| 2016 | 0.0% |
| 2017 | 50.0% |
| 2018 | 0.0% |
| 2019 | 66.7% |
| 2020 | 50.0% |
2020: 50.0%. Across these years the share ran from 0.0% to 66.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 2 tests were reported to CDC for Adams County over 2020, 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: 2020. Measured data period: 2005 to 2020 (every CDC figure on file).
Adams County, Compared
Adams County radon figures, compared
Calculated by Radon411CDC's largest figure for Adams County rests on 7 tests over the 2008 to 2017 laboratory totals, 1 of them at or above 4 pCi/L, so each test moves its share by 14.3 points and no rank or comparison is drawn from it. Results reached as high as 6.9 pCi/L, with a middle value of 1.5 pCi/L.
Whitman County, the one bordering county with a figure over the 2008 to 2017 laboratory totals, reported 22.4% of its tests at or above 4 pCi/L. Farther out, Walla Walla County (52 miles away) at 16.4%, Benton County (68 miles away) at 19.5% and Spokane County (70 miles away) at 41.4% have figures too. Pooled across 39 Washington counties, 25.5% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Pend Oreille County reported the highest share (63.2%) and Snohomish County the lowest (2.3%). EPA's 1993 map puts Adams 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.
Adams County, Geology
The ground under Adams County
PredictedUSGS's geologic map puts all of Adams County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Columbia Basin, to which USGS gives a radon index of 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Columbia Basin | Basaltic rocks low in uranium content. Uranium content of soils is moderately elevated. | Moderate | 10 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Adams County beside the ground around it
Across Washington 13.7% of the land is rated high; none of Adams County's is. Of the 4 counties that border it, 3 have more high-potential ground, Lincoln County the most at 4.7%.
The map rates the ground, not the air in any home.
Local help
Adams County, Local resources
Radon testing and mitigation in Adams County
- Radon ProgramRadon Program, run by Washington State Department of Health, offers free or discounted test kits, and answers questions about testing and mitigation in Washington.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
We have a limited supply of free radon test kits.
- Compare kits
- See the Washington directoryNo professionals are listed in Washington yet. The state program can point you to registered testers and mitigators.
What Washington's program says
- Phone
- 360-236-3200
- doh.radon@doh.wa.gov
What it means
Adams County, Questions
Questions about radon in Adams County
Are radon levels high in Adams County?
In 2020, 50.0% of the radon tests reported to CDC for Adams County, Washington were at or above 4 pCi/L, and the median reported pre-mitigation result was 10.5 pCi/L. Whitman County, the one bordering county with a figure over the 2008 to 2017 laboratory totals, reported 22.4% of its tests at or above 4 pCi/L.
Which counties border Adams County?
Adams County borders 4 counties: Lincoln County, Franklin County, Whitman County and Grant County.
Products
Adams County, Products
Testing a home in Adams County
No CDC figure names Adams County; the nearest county with one, Whitman County (49 miles away), reported 22.4% 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 Adams County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Monitor
Wave Plus battery radon and air quality 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
Adams County, Bordering counties
Counties bordering Adams County
Calculated by Radon411- Radon levels in Lincoln CountyEPA zone 2
40.0%at or above 4 pCi/L
Median 3.1 pCi/L · 15 tests
- Radon levels in Grant CountyEPA zone 2
23.5%at or above 4 pCi/L
Median 2.7 pCi/L · 17 tests
- Radon levels in Whitman CountyEPA zone 2
22.4%at or above 4 pCi/L
Median 1.5 pCi/L · 58 tests
- Radon levels in Franklin CountyEPA zone 2
10.5%at or above 4 pCi/L
Median 1.8 pCi/L · 19 tests
Adams County, Cities and towns
Cities and towns in Adams County
The Census Bureau estimates 21,488 residents in Adams County for July 1, 2025, 878 more than in 2020 (+4.3%). That works out to 11 people per square mile of land. Its largest town, Othello, has 9,237 residents, 43.0% of the total. Together its 5 incorporated places hold 55.1% of those residents; the other 44.9% live outside any of them. Reported testing is thin here: 7 tests over 2008 to 2017, or 0.3 for every 1,000 residents (2025 estimate), where Washington as a whole comes to 1.0.
From Othello to Hatton, CDC publishes no figure by town: each reads Adams County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Othello | 9,237 | +8.0% | 43.0% |
| Ritzville | 1,709 | −2.1% | 8.0% |
| Lind | 522 | −2.6% | 2.4% |
| Washtucna | 199 | −2.5% | 0.9% |
| Hatton | 170 | +97.7% | 0.8% |
5 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).
Adams County, Homes
Homes in Adams County
Of Adams County's 6,844 homes, 61% are detached houses, against 62% across Washington; 23% are mobile homes. The homes are older than Washington's as a whole: half were built before 1976 (1984 for Washington), and 28% date from before 1960. 69% of occupied homes are lived in by their owner (Washington: 64%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Adams County | Washington |
|---|---|---|
| Housing units | 6,844 | 3,262,667 |
| Detached houses | 61% | 62% |
| In buildings of 5 or more | 7% | 22% |
| Mobile homes | 23% | 6% |
| Built before 1960 | 28% | 21% |
| Built since 2000 | 21% | 28% |
| Middle year built | 1976 | 1984 |
| Owner-occupied | 69% | 64% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.