Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
Locations and reports
Radon Levels in Gilliam County, Oregon
EPA puts Gilliam County in Zone 2, its middle radon zone, and only 4 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
10.0%
Wasco County
- Wasco
- 10.0%
1 of 5 neighbours have 30+ tests, 2016
Nearest county
10.0%
Wasco County, 49 miles
- Wasco
- 10.0%
- Oregon
- 21.5%
Share at 4+ pCi/L, 30 tests, 2016
Ground above low
100.0%
37.7 pts above Oregon
- Gilliam
- 100.0%
- Oregon
- 62.3%
Share of land USGS rates moderate or high potential
Tests reported
21
Too few for a share
- Gilliam
- 21
- Needed
- 30
2022
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 Gilliam 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
Gilliam County, At a glance
Gilliam County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Gilliam 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 Gilliam County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2016 | 0.0% |
| 2018 | 0.0% |
| 2020 | 0.0% |
| 2022 | 0.0% |
| 2023 | 0.0% |
2023: 0.0%. Across these years the share ran from 0.0% to 0.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 4 tests were reported to CDC for Gilliam County over 2023, 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: 2023. Measured data period: 2016 to 2023 (every CDC figure on file).
Gilliam County, Compared
Gilliam County radon figures, compared
Calculated by Radon411CDC's largest figure for Gilliam County rests on 21 tests in 2022, 0 of them at or above 4 pCi/L, so each test moves its share by 4.8 points and no rank or comparison is drawn from it. Results reached as high as 2.1 pCi/L, with a middle value of 0.7 pCi/L.
Wasco County, the one bordering county with a figure in 2016, reported 10.0% of its tests at or above 4 pCi/L. Farther out, Hood River County (71 miles away) at 20.8%, Clackamas County (99 miles away) at 17.9% and Union County (107 miles away) at 39.1% have figures too. Pooled across 35 Oregon counties, 21.5% of reported tests reached that level; across every county in the country with a figure, 31.2%.
Statewide for the same period, Union County reported the highest share (39.1%) and Deschutes County the lowest (6.7%). EPA's 1993 map puts Gilliam 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.
Gilliam County, Geology
The ground under Gilliam County
PredictedUSGS's geologic map puts all of Gilliam County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Deschutes Umatilla Plateau, 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 |
|---|---|---|---|---|
| Deschutes Umatilla Plateau | Tertiary basalt, basaltic breccia, tuffaceous sedimentary rocks and tuff. Elevated uranium in soils. | Moderate | 9 | 99.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Gilliam County beside the ground around it
Gilliam County has more moderate-potential ground than Oregon as a whole: 100% of its land against 62.3%. Of the 5 counties that border it, none has as large a share of moderate-potential ground; Sherman County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Gilliam County, Local resources
Radon testing and mitigation in Gilliam County
- Oregon Radon Awareness ProgramOregon Radon Awareness Program, run by Oregon Health Authority, offers free or discounted test kits, and answers questions about testing and mitigation in Oregon.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Oregon Radon Awareness Program provides a FREE short-term radon test kit to those living in areas of Oregon where little radon testing has been done.
- Compare kits
- Professionals in Oregon38 professionals are listed in Oregon.
What Oregon's program says
- Radon.program@dhsoha.state.or.us
What it means
Gilliam County, Questions
Questions about radon in Gilliam County
Are radon levels high in Gilliam County?
In 2023, 0.0% of the radon tests reported to CDC for Gilliam County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.5 pCi/L. Wasco County, the one bordering county with a figure in 2016, reported 10.0% of its tests at or above 4 pCi/L.
Which counties border Gilliam County?
Gilliam County borders 5 counties: Sherman County, OR, Morrow County, OR, Klickitat County, WA, Wasco County, OR and Wheeler County, OR.
Products
Gilliam County, Products
Testing a home in Gilliam County
No CDC figure names Gilliam County; the nearest county with one, Wasco County (49 miles away), reported 10.0% of its tests at or above 4 pCi/L in 2016, 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 Gilliam 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
RadonEye RD200 plug-in continuous radon monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Gilliam County, Bordering counties
Counties bordering Gilliam County
Calculated by Radon411- Radon levels in Klickitat County, WAEPA zone 2
14.8%at or above 4 pCi/L
Median 2.1 pCi/L · 27 tests
- Radon levels in Wasco County, OREPA zone 2
10.0%at or above 4 pCi/L
Median 0.8 pCi/L · 30 tests
- Radon levels in Sherman County, OREPA zone 2
0.0%at or above 4 pCi/L
Median 0.7 pCi/L · 2 tests
- Radon levels in Morrow County, OREPA zone 2
0.0%at or above 4 pCi/L
Median 1.9 pCi/L · 1 test
- Radon levels in Wheeler County, OREPA zone 2
No CDC figure for 2016; its page reads it against its own neighbours.
Gilliam County, Cities and towns
Cities and towns in Gilliam County
About 1,971 people live in Gilliam County by the Census Bureau's estimate for July 1, 2025, 43 fewer than in 2020 (−2.1%). Spread over its land, that is 1.6 people to the square mile. Its largest town, Condon, has 704 residents, 35.7% of the total. Together its 3 incorporated places hold 72.2% of those residents; the other 27.8% live outside any of them. Testing is reported here more often than across the state: CDC's 21 reported tests for 2022 come to 10.7 for every 1,000 residents (2025 estimate), against 1.6 for Oregon.
From Condon to Lonerock, CDC publishes no figure by town: each reads Gilliam County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Condon | 704 | −1.8% | 35.7% |
| Arlington | 696 | −2.2% | 35.3% |
| Lonerock | 24 | Level | 1.2% |
3 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).
Gilliam County, Homes
Homes in Gilliam County
Gilliam County is a place of houses on their own lots: 79% of its 1,111 homes are detached single-family houses, against 63% across Oregon. The homes are older than Oregon's as a whole: half were built before 1958 (1980 for Oregon), and 54% date from before 1960. Owners live in 76% of the occupied homes (Oregon: 63%), so for most households a test and a fix are their own to order.
| Homes | Gilliam County | Oregon |
|---|---|---|
| Housing units | 1,111 | 1,838,631 |
| Detached houses | 79% | 63% |
| In buildings of 5 or more | 3% | 17% |
| Mobile homes | 16% | 8% |
| Built before 1960 | 54% | 23% |
| Built since 2000 | 13% | 24% |
| Middle year built | 1958 | 1980 |
| Owner-occupied | 76% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.