Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Washington County, Colorado
EPA puts Washington County in Zone 1, its highest radon zone, and only 2 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
Share at 4+ pCi/L
62.8%
15.8 pts above CO
- Washington
- 62.8%
- Colorado
- 47.0%
86 tests, 2008 to 2017
Median result
4.6pCi/L
Action level reached
- Washington
- 4.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
86
39th of 50 by tests
- Washington
- 86
- Jefferson
- 11,723
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Colorado
5 of 50
Top quarter
- Washington
- 62.8%
- Kit Carson
- 71.4%
By share, of 50 with 30+ tests
Read a result for Washington County
Starts at Washington County's median, 4.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.6 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. Washington County's median reported result, 2008 to 2017.
The data
Washington County, At a glance
Washington County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Washington County in
USGS geologic potential: High across 90% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Washington County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2016 | 0.0% |
| 2017 | 50.0% |
| 2018 | 38.5% |
| 2019 | 75.0% |
| 2020 | 57.1% |
| 2021 | 66.7% |
| 2022 | 100.0% |
| 2023 | 100.0% |
2023: 100.0%. Across these years the share ran from 0.0% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 2 tests were reported to CDC for Washington 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: 2005 to 2023 (every CDC figure on file).
Washington County, Compared
Washington County radon figures, compared
Calculated by Radon411More than half: 62.8% of the 86 radon tests reported to CDC for Washington County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 5th of 50 Colorado counties with 30 or more tests for the same period. That is 15.8 points above the 47.0% pooled from 63 Colorado counties.
The newest figure, in 2023, counts only 2 tests (100.0% at or above 4 pCi/L), too few to compare, so this reading uses the 86-test figure.
The median result, 4.6 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 90.1 pCi/L. The rest split 15.1% under 2 pCi/L and 22.1% from 2 to 4 (Colorado: 31.4% and 21.5%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 62.8% share point the same way here.
1 of its 6 bordering counties with figures ran higher, led by Kit Carson County at 71.4%; Adams County reported 41.4%. Statewide for the same period, Kit Carson County reported the highest share (71.4%) and Alamosa County the lowest (26.6%).
The busiest year on file was 2018, with 13 tests reported; the quietest, 2016, had 1.
Nationally, every county with a figure for the same period pools to 35.7%; Washington County sits 27.1 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Washington County, State data
Colorado's own radon test data
MeasuredWhat Colorado's own agencies publish about radon tests in Washington County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What Colorado CDPHE reports for Washington County
Radon data (county results): radon test results received from radon testing labs, primarily short-term household tests taken by the homeowner. Period: 2005-2025.
Share over 4 pCi/L
56.9%
29 of 51 tests
Median result
4.5 pCi/L
Highest result
47.3 pCi/L
Tests behind these figures
51 tests
- CDPHE says these data do not give actual radon levels in homes that have not been tested.
- When possible, only tests conducted before a mitigation system was installed are used.
- Some counties have very small numbers of test results, and their summaries may be less representative.
- These figures describe tests reported to Colorado CDPHE in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.
Measured: Colorado CDPHE data, 2005-2025.
Washington County, Geology
The ground under Washington County
PredictedMost of the ground under Washington County is one class on USGS's geologic map: 90.4% of its land is high radon potential, with 9.6% moderate. The map puts 52.8% of Washington County in the area it calls Ogallala Formation and 37.6% in High Plains, with one smaller area beside them. USGS gives both a radon index of 12, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Ogallala Formation | Tertiary sandstone, in part covered by windblown eolian sand and loess deposits. | High | 12 | 52.8% |
| High Plains | Quaternary deposits and Cretaceous marine shales that locally have a high radiometric signature. | High | 12 | 37.6% |
| Tertiary Rocks | Tertiary sandstone, siltstone, and volcanic ash. | Moderate | 11 | 9.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Washington County beside the ground around it
Washington County has more high-potential ground than Colorado as a whole: 90.4% of its land against 74.8%. Of the 7 counties that border it, 5 have more high-potential ground, Adams County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Washington County, Local resources
Radon testing and mitigation in Washington County
- Colorado's radon programColorado Department of Public Health and EnvironmentColorado's radon program licenses or certifies radon professionals, offers free or discounted test kits and states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in Colorado.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Order a discounted radon test kit
- Compare kits
- Professionals in Colorado25 professionals are listed in Colorado.
What Colorado's program says
- Licensing of radon professionals
Listed contractors are certified by the National Radon Proficiency Program or the National Radon Safety Board, and must be licensed by the Colorado Department of Regulatory Agencies.
- Disclosure when a home is sold or rented
As of August 7, 2023, landlords in Colorado are required to disclose radon information when a tenant signs a lease agreement.
What it means
Washington County, Questions
Questions about radon in Washington County
Are radon levels high in Washington County?
In 2023, 100.0% of the radon tests reported to CDC for Washington County, Colorado were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.3 pCi/L. Of 50 Colorado counties with 30 or more tests for the same period, 4 reported a higher share; pooled, the state comes to 47.0%.
Which counties border Washington County?
Washington County borders 7 counties: Morgan County, Yuma County, Kit Carson County, Logan County, Adams County, Lincoln County and Arapahoe County.
Products
Washington County, Products
Testing a home in Washington County
In Washington County, 62.8% of 86 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 47.0% pooled across Colorado. In Zone 1 the year-round level in Washington County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
Monitor
lüft plug-in radon and indoor air quality monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Wi-Fi, Bluetooth
- App only
First reading: Within 90 minutes
Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Washington County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Washington County
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Washington County, Bordering counties
Counties bordering Washington County
Calculated by Radon411- Radon levels in Kit Carson CountyEPA zone 1
71.4%at or above 4 pCi/L
Median 5.3 pCi/L · 42 tests · 8.6 points above Washington County
- Radon levels in Morgan CountyEPA zone 1
59.1%at or above 4 pCi/L
Median 4.9 pCi/L · 208 tests · 3.7 points below Washington County
- Radon levels in Logan CountyEPA zone 1
58.8%at or above 4 pCi/L
Median 4.8 pCi/L · 80 tests · 4.0 points below Washington County
- Radon levels in Yuma CountyEPA zone 1
57.1%at or above 4 pCi/L
Median 4.0 pCi/L · 35 tests · 5.7 points below Washington County
- Radon levels in Lincoln CountyEPA zone 1
50.0%at or above 4 pCi/L
Median 4.0 pCi/L · 16 tests · 12.8 points below Washington County
- Radon levels in Arapahoe CountyEPA zone 1
45.3%at or above 4 pCi/L
Median 3.4 pCi/L · 9,988 tests · 17.5 points below Washington County
- Radon levels in Adams CountyEPA zone 1
41.4%at or above 4 pCi/L
Median 3.0 pCi/L · 4,765 tests · 21.4 points below Washington County
Washington County, Cities and towns
Cities and towns in Washington County
About 4,732 people live in Washington County by the Census Bureau's estimate for July 1, 2025, 78 fewer than in 2020 (−1.6%). Spread over its land, that is 1.9 people to the square mile. Its largest town, Akron, has 1,725 residents, 36.5% of the total. Together its 2 incorporated places hold 47.1% of those residents; the other 52.9% live outside any of them. CDC's 86 reported tests for 2008 to 2017 work out to 18.2 per 1,000 residents (2025 estimate), close to Colorado's 16.0.
From Akron to Otis, CDC publishes no figure by town: each reads Washington County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Akron | 1,725 | −2.0% | 36.5% |
| Otis | 502 | −2.3% | 10.6% |
2 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).
Washington County, Homes
Homes in Washington County
Washington County is a place of houses on their own lots: 82% of its 2,280 homes are detached single-family houses, against 62% across Colorado. The homes are older than Colorado's as a whole: half were built before 1960 (1987 for Colorado), and 50% date from before 1960. 72% of occupied homes are lived in by their owner (Colorado: 66%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Washington County | Colorado |
|---|---|---|
| Housing units | 2,280 | 2,545,124 |
| Detached houses | 82% | 62% |
| In buildings of 5 or more | 2% | 22% |
| Mobile homes | 11% | 4% |
| Built before 1960 | 50% | 16% |
| Built since 2000 | 11% | 31% |
| Middle year built | 1960 | 1987 |
| Owner-occupied | 72% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.