Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Bastrop County, Texas
EPA puts Bastrop County in Zone 3, its lowest radon zone, and only 13 radon tests from it are 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
Highest bordering
9.3%
Travis County
- Travis
- 9.3%
- Williamson
- 2.0%
2 of 5 neighbours have 30+ tests, 2007 to 2016
Nearest county
9.3%
Travis County, 32 miles
- Travis
- 9.3%
- Texas
- 10.4%
Share at 4+ pCi/L, 408 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
- Bastrop
- 0.0%
- Texas
- 27.3%
Share of land USGS rates moderate or high potential
Tests reported
13
Too few for a share
- Bastrop
- 13
- 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 Bastrop 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
Bastrop County, At a glance
Bastrop 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 Bastrop County, 2008 to 2017, laboratory
CDC holds 13 reported tests for Bastrop County over the 2008 to 2017 laboratory totals, with a median of 6.5 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Bastrop County beside the counties around it is how this page reads it.
What these figures count
Only 13 tests were reported to CDC for Bastrop 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).
Bastrop County, Compared
Bastrop County radon figures, compared
Calculated by Radon411CDC's largest figure for Bastrop County rests on 13 tests over the 2008 to 2017 laboratory totals, 8 of them at or above 4 pCi/L, so each test moves its share by 7.7 points and no rank or comparison is drawn from it. Results reached as high as 48.0 pCi/L, with a middle value of 6.5 pCi/L.
Of the counties bordering it, 2 have a figure over the 2007 to 2016 laboratory totals: Travis County reported the largest share at or above 4 pCi/L, 9.3%, and Williamson County the smallest, 2.0%. Farther out, Bell County (65 miles away) at 14.3%, Brazos County (71 miles away) at 0.0% and Bexar County (85 miles away) at 6.6% have figures too. 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 Bastrop 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.
Bastrop County, Geology
The ground under Bastrop County
PredictedUSGS's geologic map puts all of Bastrop County's mapped land in one class: low radon potential. All of it lies in the area the map calls East Texas Province, to which USGS gives a radon index of 6, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| East Texas Province | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 6 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Bastrop County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Bastrop County's is. Of the 5 counties that border it, 2 have more moderate-potential ground, Williamson County the most at 15.4%.
The map rates the ground, not the air in any home.
Local help
Bastrop County, Local resources
Radon testing and mitigation in Bastrop 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
Bastrop County, Questions
Questions about radon in Bastrop County
Are radon levels high in Bastrop County?
Over the 2008 to 2017 laboratory totals, 61.5% of the radon tests reported to CDC for Bastrop County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 6.5 pCi/L. Of the counties bordering it, 2 have a figure over the 2007 to 2016 laboratory totals: Travis County reported the largest share at or above 4 pCi/L, 9.3%, and Williamson County the smallest, 2.0%.
Which counties border Bastrop County?
Bastrop County borders 5 counties: Lee County, Caldwell County, Travis County, Fayette County and Williamson County.
Products
Bastrop County, Products
Testing a home in Bastrop County
No CDC figure names Bastrop County; the nearest county with one, Travis County (32 miles away), reported 9.3% 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 Bastrop 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
Monitor
EcoQube Flex battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 15 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Bastrop County, Bordering counties
Counties bordering Bastrop County
Calculated by Radon411- Radon levels in Travis CountyEPA zone 3
9.3%at or above 4 pCi/L
Median 0.8 pCi/L · 408 tests
- Radon levels in Williamson CountyEPA zone 3
2.0%at or above 4 pCi/L
Median 0.7 pCi/L · 98 tests
- Radon levels in Caldwell CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 1.1 pCi/L · 2 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 Lee CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Bastrop County, Cities and towns
Cities and towns in Bastrop County
Bastrop County is growing: the Census Bureau puts it at 118,908 residents on July 1, 2025, up 21.3% from 98,060 in 2020. That works out to 134 people per square mile of land. Austin, the largest place on its list (1,002,632 residents in all), extends beyond Bastrop County, so no share of the total is worked out for it. CDC's 13 reported tests for 2008 to 2017 work out to 0.1 per 1,000 residents (2025 estimate), close to Texas' 0.1.
From Austin to Mustang Ridge, CDC publishes no figure by town: each reads Bastrop County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Austinextends beyond Bastrop County | 1,002,632 | +4.2% | Counted whole |
| Bastrop | 13,383 | +36.7% | 11.3% |
| Elginextends beyond Bastrop County | 13,327 | +35.9% | Counted whole |
| Smithville | 4,367 | +7.5% | 3.7% |
| Mustang Ridgeextends beyond Bastrop County | 1,025 | +7.0% | Counted whole |
Places in Bastrop County with a city page: 1 of 1
5 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 Bastrop County is counted whole, so it has no share.
Bastrop County, Homes
Homes in Bastrop County
Of Bastrop County's 38,269 homes, 66% are detached houses, against 65% across Texas; 27% are mobile homes. Half of its homes were built before 1996, close to Texas' 1990: 11% date from before 1960 and 44% from 2000 or later. Owners live in 76% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.
| Homes | Bastrop County | Texas |
|---|---|---|
| Housing units | 38,269 | 11,890,808 |
| Detached houses | 66% | 65% |
| In buildings of 5 or more | 3% | 21% |
| Mobile homes | 27% | 7% |
| Built before 1960 | 11% | 13% |
| Built since 2000 | 44% | 37% |
| Middle year built | 1996 | 1990 |
| 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.