Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
Locations and reports
Radon Levels in Douglas County, Washington
EPA puts Douglas County in Zone 2, its middle radon zone, and only 8 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
35.0%
Okanogan County
- Okanogan
- 35.0%
- Chelan
- 14.6%
2 of 4 neighbours have 30+ tests, 2008 to 2017
Nearest county
14.6%
Chelan County, 44 miles
- Chelan
- 14.6%
- Washington
- 25.5%
Share at 4+ pCi/L, 48 tests, 2008 to 2017
Ground above low
92.7%
40.0 pts above Washington
- Douglas
- 92.7%
- Washington
- 52.7%
Share of land USGS rates moderate or high potential
Tests reported
14
Too few for a share
- Douglas
- 14
- 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 Douglas 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
Douglas County, At a glance
Douglas County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Douglas County is a
USGS geologic potential: Moderate across 87% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Douglas County, 2020
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 0.0% |
| 2015 | 0.0% |
| 2016 | 0.0% |
| 2017 | 11.1% |
| 2018 | 0.0% |
| 2019 | 0.0% |
| 2020 | 25.0% |
2020: 25.0%. Across these years the share ran from 0.0% to 25.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 8 tests were reported to CDC for Douglas 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).
Douglas County, Compared
Douglas County radon figures, compared
Calculated by Radon411CDC's largest figure for Douglas County rests on 14 tests over the 2008 to 2017 laboratory totals, 5 of them at or above 4 pCi/L, so each test moves its share by 7.1 points and no rank or comparison is drawn from it. Results reached as high as 39.8 pCi/L, with a middle value of 2.3 pCi/L.
Of the counties bordering it, 2 have a figure over the 2008 to 2017 laboratory totals: Okanogan County reported the largest share at or above 4 pCi/L, 35.0%, and Chelan County the smallest, 14.6%. Farther out, Snohomish County (96 miles away) at 2.3%, Stevens County (97 miles away) at 36.2% and King County (100 miles away) at 2.6% 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 Douglas County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 87% of the county's land moderate radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Douglas County, Geology
The ground under Douglas County
PredictedMost of the ground under Douglas County is one class on USGS's geologic map: 87.4% of its land is moderate radon potential, with 5.3% high and 7.3% low. The map puts 87.4% of Douglas County in the area it calls Columbia Basin and 7.3% in Cascade Mountains, with one smaller area beside them. USGS gives the first a radon index of 10, in the moderate band (9 to 11), and the second 6, in the low band (5 to 8).
| 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 | 87.4% |
| Cascade Mountains | Northern Cascade Mountains are Mesozoic metamorphic rocks intruded by Mesozoic and Tertiary granitic rocks. Southern Cascade Mountains are composed primarily of Tertiary and Holocene volcanic rocks. | Low | 6 | 7.3% |
| Okanogan Highland | Glaciofluvial outwash and granitic material. Outwash is generally uranium-bearing. | High | 16 | 5.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Douglas County beside the ground around it
On high-potential ground Douglas County is close to Washington as a whole: 5.3% of its land against 13.7%. Of the 4 counties that border it, 1 has more high-potential ground, Okanogan County the most at 38.7%.
The map rates the ground, not the air in any home.
Local help
Douglas County, Local resources
Radon testing and mitigation in Douglas 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
Douglas County, Questions
Questions about radon in Douglas County
Are radon levels high in Douglas County?
In 2020, 25.0% of the radon tests reported to CDC for Douglas County, Washington were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.9 pCi/L. Of the counties bordering it, 2 have a figure over the 2008 to 2017 laboratory totals: Okanogan County reported the largest share at or above 4 pCi/L, 35.0%, and Chelan County the smallest, 14.6%.
Which counties border Douglas County?
Douglas County borders 4 counties: Grant County, Chelan County, Okanogan County and Kittitas County.
Products
Douglas County, Products
Testing a home in Douglas County
No CDC figure names Douglas County; the nearest county with one, Chelan County (44 miles away), reported 14.6% 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 Douglas 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
MonitorAranet
Radon Plus battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Approved
- Battery
- 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
Douglas County, Bordering counties
Counties bordering Douglas County
Calculated by Radon411- Radon levels in Okanogan CountyEPA zone 1
35.0%at or above 4 pCi/L
Median 2.3 pCi/L · 40 tests
- Radon levels in Kittitas CountyEPA zone 2
25.0%at or above 4 pCi/L
Median 1.4 pCi/L · 8 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 Chelan CountyEPA zone 3
14.6%at or above 4 pCi/L
Median 1.8 pCi/L · 48 tests
Douglas County, Cities and towns
Cities and towns in Douglas County
Douglas County is growing: the Census Bureau puts it at 46,473 residents on July 1, 2025, up 8.0% from 43,033 in 2020. That works out to 26 people per square mile of land. Its largest town, East Wenatchee, has 14,414 residents, 31.0% of the total. Reported testing is thin here: 14 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 East Wenatchee to Mansfield, CDC publishes no figure by town: each reads Douglas County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| East Wenatchee | 14,414 | +2.0% | 31.0% |
| Bridgeport | 2,274 | +6.7% | 4.9% |
| Rock Island | 1,753 | +36.0% | 3.8% |
| Coulee Damextends beyond Douglas County | 1,241 | +2.3% | Counted whole |
| Waterville | 1,156 | +2.5% | 2.5% |
| Mansfield | 342 | +3.6% | 0.7% |
6 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). A place that extends beyond Douglas County is counted whole, so it has no share.
Douglas County, Homes
Homes in Douglas County
Of Douglas County's 17,721 homes, 68% are detached houses, against 62% across Washington; 15% are mobile homes. Half of its homes were built before 1984, close to Washington's 1984: 21% date from before 1960 and 31% from 2000 or later. 68% 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 | Douglas County | Washington |
|---|---|---|
| Housing units | 17,721 | 3,262,667 |
| Detached houses | 68% | 62% |
| In buildings of 5 or more | 7% | 22% |
| Mobile homes | 15% | 6% |
| Built before 1960 | 21% | 21% |
| Built since 2000 | 31% | 28% |
| Middle year built | 1984 | 1984 |
| Owner-occupied | 68% | 64% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.