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 Colorado County, Texas
EPA puts Colorado County in Zone 3, its lowest radon zone, and only 1 radon test from it is on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Nearest county
3.4%
Fort Bend County, 46 miles
- Fort Bend
- 3.4%
- Texas
- 10.4%
Share at 4+ pCi/L, 117 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
- Colorado
- 0.0%
- Texas
- 27.3%
Share of land USGS rates moderate or high potential
Tests reported
1
Too few for a share
- Colorado
- 1
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Colorado 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
Colorado County, At a glance
Colorado County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Colorado County, 2008 to 2017, laboratory
CDC holds 1 reported test for Colorado County over the 2008 to 2017 laboratory totals, a result of 1.5 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Colorado County beside the counties around it is how this page reads it.
What these figures count
Only 1 test was reported to CDC for Colorado County over 2008 to 2017 (laboratory totals), 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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Colorado County, Compared
Colorado County radon figures, compared
Calculated by Radon411CDC's largest figure for Colorado County rests on 1 test over the 2008 to 2017 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 100.0 points and no rank or comparison is drawn from it. Results reached as high as 1.5 pCi/L, with a middle value of 1.5 pCi/L.
The nearest counties with a figure are Fort Bend County (46 miles away) at 3.4%, Harris County (70 miles away) at 3.1% and Brazoria County (71 miles away) at 6.3%. Pooled across 140 Texas counties, 10.4% of reported tests reached that level; across every county in the country with a figure, 35.8%.
Statewide for the same period, Randall County reported the highest share (71.4%) and Nueces County the lowest (0.0%). EPA's 1993 map puts Colorado County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 100% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Colorado County, Geology
The ground under Colorado County
PredictedUSGS's geologic map puts all of Colorado County's mapped land in one class: low radon potential. All of it lies in the area the map calls Coastal Plain, to which USGS gives a radon index of 7, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Coastal Plain | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 7 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Colorado County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Colorado County's is. None of the 5 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Colorado County, Local resources
Radon testing and mitigation in Colorado County
- Texas Radon GroupTexas Radon Group, run by Texas Tech University, does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Texas.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The Texas Radon Group offers free radon test kits for Texas individuals who qualify.
- Compare kits
- Professionals in Texas7 professionals are listed in Texas.
What Texas's program says
- Licensing of radon professionals
There are no radon certification requirements for the State of Texas at this time, but the National Radon Proficiency Program lists radon testers and mitigators within Texas that have passed a rigorous national certification program.
What it means
Colorado County, Questions
Questions about radon in Colorado County
Are radon levels high in Colorado County?
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Colorado County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Of the 8 nearest counties with a figure, within 96 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 9.3%.
Which counties border Colorado County?
Colorado County borders 5 counties: Austin County, Lavaca County, Wharton County, Fayette County and Jackson County.
Products
Colorado County, Products
Testing a home in Colorado County
No CDC figure names Colorado County; the nearest county with one, Fort Bend County (46 miles away), reported 3.4% of its tests at or above 4 pCi/L over the 2007 to 2016 laboratory totals, the only reading nearby until a test of this home. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Colorado County.
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
MonitorForensics Detectors
FD-65-RADON rechargeable radon detector with a color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Colorado County, Bordering counties
Counties bordering Colorado County
Calculated by Radon411- Radon levels in Austin CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 2 tests
- Radon levels in Lavaca CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 3 tests
- Radon levels in Wharton CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.5 pCi/L · 9 tests
- Radon levels in Fayette CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 6 tests
- Radon levels in Jackson CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
Colorado County, Cities and towns
Cities and towns in Colorado County
The Census Bureau estimates 21,439 residents in Colorado County for July 1, 2025, 798 more than in 2020 (+3.9%). That works out to 22 people per square mile of land. No town dominates: Columbus, the largest, has 3,821 residents, 17.8% of the total. Together its 3 incorporated places hold 44.6% of those residents; the other 55.4% live outside any of them. Reported testing is thin here: 1 test over 2008 to 2017, or under 0.1 for every 1,000 residents (2025 estimate), where Texas as a whole comes to 0.1.
From Columbus to Weimar, CDC publishes no figure by town: each reads Colorado County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Columbus | 3,821 | +3.6% | 17.8% |
| Eagle Lake | 3,546 | +3.2% | 16.5% |
| Weimar | 2,197 | +6.3% | 10.2% |
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).
Colorado County, Homes
Homes in Colorado County
Of Colorado County's 10,066 homes, 74% are detached houses, against 65% across Texas; 18% are mobile homes. Half of its homes were built before 1983, close to Texas' 1990: 29% date from before 1960 and 27% from 2000 or later. Owners live in 81% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.
| Homes | Colorado County | Texas |
|---|---|---|
| Housing units | 10,066 | 11,890,808 |
| Detached houses | 74% | 65% |
| In buildings of 5 or more | 3% | 21% |
| Mobile homes | 18% | 7% |
| Built before 1960 | 29% | 13% |
| Built since 2000 | 27% | 37% |
| Middle year built | 1983 | 1990 |
| Owner-occupied | 81% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.