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
Locations and reports
Radon Levels in Clear Creek County, Colorado
EPA puts Clear Creek County in Zone 1, its highest radon zone, and high results are common there: 41.2% of the 51 radon tests reported to CDC (2023) came back at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
41.2%
2.3 pts above CO
- Clear Creek
- 41.2%
- Colorado
- 38.9%
51 tests, 2023
Median result
3.0pCi/L
Below action level
- Clear Creek
- 3.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
51
34th of 38 by tests
- Clear Creek
- 51
- Jefferson
- 3,068
Reported to CDC before any fix, 2023
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
18 of 38
Middle half
- Clear Creek
- 41.2%
- Park
- 57.5%
By share, of 38 with 30+ tests
Read a result for Clear Creek County
Starts at Clear Creek County's median, 3.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.0 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Clear Creek County's median reported result, 2023.
The data
Clear Creek County, At a glance
Clear Creek County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Clear Creek County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Clear Creek County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 46.7% |
| 2015 | 54.1% |
| 2016 | 25.0% |
| 2017 | 46.4% |
| 2018 | 45.8% |
| 2019 | 21.4% |
| 2020 | 58.2% |
| 2021 | 50.0% |
| 2022 | 42.5% |
| 2023 | 41.2% |
2023: 41.2%. Across these years the share ran from 21.4% to 58.2%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 51 tests reported to CDC for Clear Creek County over 2023, many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Clear Creek County, Compared
Clear Creek County radon figures, compared
Calculated by Radon411In Clear Creek County, about 4 in 10 reported tests in 2023 (21 of 51) were at or above EPA's action level. Against the national pool of 33.4%, the gap is 7.8 points higher. Across 61 Colorado counties pooled together, 38.9% of tests reached that level, so Clear Creek County runs 2.3 points above its state.
Of 5 neighbours with a figure, 3 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 26.4% (Gilpin County) to 57.5% (Park County). By share, Clear Creek County is 18th of 38 Colorado counties with 30 or more tests for the same period.
Year by year, 2015 opened at 54.1% and 2023 closed at 41.2% (down 12.9 points), with 2020 the high at 58.2%. Half the tests came in under 3.0 pCi/L and half over it; the single highest reached 132.3 pCi/L. Below the action level, 17 tests (33.3%) came in under 2 pCi/L, against 39.2% statewide, and 13 tests (25.5%) fell between 2 and 4, against 22.0% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 41.2% share point the same way here. USGS geology rates 100% of the county's land high radon potential. CDC also counts 23 tests taken after mitigation in Clear Creek County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2019, with 201 tests reported; the quietest, 2014, had 15.
Clear Creek CountyColorado, pooled
| Year | Tests | Clear Creek County, at or above 4 pCi/L | Colorado, pooled |
|---|---|---|---|
| 2015 | 37 | 54.1% | 47.2% |
| 2018 | 72 | 45.8% | 44.2% |
| 2019 | 201 | 21.4% | 44.1% |
| 2020 | 79 | 58.2% | 41.9% |
| 2021 | 60 | 50.0% | 47.3% |
| 2022 | 73 | 42.5% | 38.6% |
| 2023 | 51 | 41.2% | 38.9% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Clear Creek County, State data
Colorado's own radon test data
MeasuredWhat Colorado's own agencies publish about radon tests in Clear Creek 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 Clear Creek 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
37.3%
265 of 710 tests
Median result
2.4 pCi/L
Highest result
240.0 pCi/L
Tests behind these figures
710 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.
Clear Creek County, Geology
The ground under Clear Creek County
PredictedUSGS's geologic map puts all of Clear Creek County's mapped land in one class: high radon potential. All of it lies in the area the map calls Rocky Mountains, to which USGS gives a radon index of 15, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Rocky Mountains | Precambrian granites, gneiss, amphibolite, variable uranium content, abundant shear zones.Sedimentary rocks shed from the granitic highlands. | High | 15 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Clear Creek County beside the ground around it
Clear Creek County has more high-potential ground than Colorado as a whole: 100% of its land against 74.8%. Of the 5 counties that border it, none has as large a share of high-potential ground; Gilpin County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Clear Creek County, Local resources
Radon testing and mitigation in Clear Creek 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
Clear Creek County, Questions
Questions about radon in Clear Creek County
Are radon levels high in Clear Creek County?
In 2023, 41.2% of the radon tests reported to CDC for Clear Creek County, Colorado were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.0 pCi/L. Of 38 Colorado counties with 30 or more tests for the same period, 17 reported a higher share; pooled, the state comes to 38.9%.
Which counties border Clear Creek County?
Clear Creek County borders 5 counties: Gilpin County, Summit County, Jefferson County, Grand County and Park County.
Products
Clear Creek County, Products
Testing a home in Clear Creek County
In Clear Creek County, 41.2% of 51 tests reported to CDC in 2023 reached 4 pCi/L, against 38.9% pooled across Colorado. In Zone 1 the year-round level in Clear Creek 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
MonitorAEGTEST
HOUND-1085 palm-sized rechargeable radon detector
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Clear Creek County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Clear Creek County
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Clear Creek County, Bordering counties
Counties bordering Clear Creek County
Calculated by Radon411- Radon levels in Park CountyEPA zone 1
57.5%at or above 4 pCi/L
Median 4.6 pCi/L · 106 tests · 16.3 points above Clear Creek County
- Radon levels in Grand CountyEPA zone 1
44.1%at or above 4 pCi/L
Median 3.3 pCi/L · 136 tests · 2.9 points above Clear Creek County
- Radon levels in Jefferson CountyEPA zone 1
41.8%at or above 4 pCi/L
Median 3.2 pCi/L · 3,068 tests · 0.6 points above Clear Creek County
- Radon levels in Summit CountyEPA zone 1
38.3%at or above 4 pCi/L
Median 2.0 pCi/L · 295 tests · 2.9 points below Clear Creek County
- Radon levels in Gilpin CountyEPA zone 1
26.4%at or above 4 pCi/L
Median 1.1 pCi/L · 129 tests · 14.8 points below Clear Creek County
Clear Creek County, Cities and towns
Cities and towns in Clear Creek County
About 8,994 people live in Clear Creek County by the Census Bureau's estimate for July 1, 2025, 364 fewer than in 2020 (−3.9%). That works out to 23 people per square mile of land. Its largest town, Idaho Springs, has 1,842 residents, 20.5% of the total. Testing is reported here more often than across the state: CDC's 51 reported tests for 2023 come to 5.7 for every 1,000 residents (2025 estimate), against 3.6 for Colorado.
From Idaho Springs to Central City, CDC publishes no figure by town: each reads Clear Creek County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Idaho Springs | 1,842 | +2.1% | 20.5% |
| Georgetown | 1,217 | +8.6% | 13.5% |
| Empire | 317 | −6.5% | 3.5% |
| Silver Plume | 180 | −10.0% | 2.0% |
- Central City (part)
5 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Clear Creek County, Homes
Homes in Clear Creek County
Clear Creek County is a place of houses on their own lots: 81% of its 5,768 homes are detached single-family houses, against 62% across Colorado. The homes are older than Colorado's as a whole: half were built before 1976 (1987 for Colorado), and 26% date from before 1960. Owners live in 83% of the occupied homes (Colorado: 66%), so for most households a test and a fix are their own to order.
| Homes | Clear Creek County | Colorado |
|---|---|---|
| Housing units | 5,768 | 2,545,124 |
| Detached houses | 81% | 62% |
| In buildings of 5 or more | 7% | 22% |
| Mobile homes | 5% | 4% |
| Built before 1960 | 26% | 16% |
| Built since 2000 | 11% | 31% |
| Middle year built | 1976 | 1987 |
| Owner-occupied | 83% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.