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
Locations and reports
Radon Levels in Gonzales County, Texas
EPA puts Gonzales County in Zone 3, its lowest radon zone, and only 6 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
Nearest county
6.6%
Bexar County, 62 miles
- Bexar
- 6.6%
- Texas
- 10.4%
Share at 4+ pCi/L, 197 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
- Gonzales
- 0.0%
- Texas
- 27.3%
Share of land USGS rates moderate or high potential
Tests reported
6
Too few for a share
- Gonzales
- 6
- 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 Gonzales 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
Gonzales County, At a glance
Gonzales 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 Gonzales County, 2008 to 2017, laboratory
CDC holds 6 reported tests for Gonzales County over the 2008 to 2017 laboratory totals, with a median of 0.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Gonzales County beside the counties around it is how this page reads it.
What these figures count
Only 6 tests were reported to CDC for Gonzales 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).
Gonzales County, Compared
Gonzales County radon figures, compared
Calculated by Radon411CDC's largest figure for Gonzales County rests on 6 tests over the 2008 to 2017 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 16.7 points and no rank or comparison is drawn from it. Results reached as high as 0.7 pCi/L, with a middle value of 0.1 pCi/L.
The nearest counties with a figure are Bexar County (62 miles away) at 6.6%, Travis County (63 miles away) at 9.3% and Williamson County (82 miles away) at 2.0%. 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 Gonzales 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.
Gonzales County, Geology
The ground under Gonzales County
PredictedUSGS's geologic map puts all of Gonzales County's mapped land in one class: low radon potential. The map puts 83.7% of Gonzales County in the area it calls East Texas Province and 16.3% in Coastal Plain. USGS gives the first a radon index of 6 and the second 7, both 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 | 83.7% |
| Coastal Plain | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 7 | 16.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Gonzales County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Gonzales County's is. None of the 7 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Gonzales County, Local resources
Radon testing and mitigation in Gonzales 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
Gonzales County, Questions
Questions about radon in Gonzales County
Are radon levels high in Gonzales County?
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Gonzales County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.1 pCi/L. Of the 8 nearest counties with a figure, within 125 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 14.3%.
Which counties border Gonzales County?
Gonzales County borders 7 counties: DeWitt County, Caldwell County, Guadalupe County, Lavaca County, Wilson County, Karnes County and Fayette County.
Products
Gonzales County, Products
Testing a home in Gonzales County
No CDC figure names Gonzales County; the nearest county with one, Bexar County (62 miles away), reported 6.6% 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 Gonzales 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
MonitorINKBIRD
INK-RD3 battery radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
First reading: Within 24 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Gonzales County, Bordering counties
Counties bordering Gonzales County
Calculated by Radon411- Radon levels in DeWitt CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 1.3 pCi/L · 2 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 Guadalupe CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.6 pCi/L · 3 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 Wilson CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
- 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 Karnes CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Gonzales County, Cities and towns
Cities and towns in Gonzales County
The Census Bureau estimates 20,159 residents in Gonzales County for July 1, 2025, 489 more than in 2020 (+2.5%). That works out to 19 people per square mile of land. Its largest town, Gonzales, has 7,239 residents, 35.9% of the total. Testing is reported here more often than across the state: CDC's 6 reported tests for 2008 to 2017 come to 0.3 for every 1,000 residents (2025 estimate), against 0.1 for Texas.
From Gonzales to Smiley, CDC publishes no figure by town: each reads Gonzales County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Gonzales | 7,239 | +1.2% | 35.9% |
| Nixonextends beyond Gonzales County | 2,406 | +2.1% | Counted whole |
| Waelder | 954 | +2.0% | 4.7% |
| Smiley | 501 | +3.9% | 2.5% |
4 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 Gonzales County is counted whole, so it has no share.
Gonzales County, Homes
Homes in Gonzales County
Of Gonzales County's 8,976 homes, 66% are detached houses, against 65% across Texas; 24% are mobile homes. The homes are older than Texas' as a whole: half were built before 1982 (1990 for Texas), and 30% date from before 1960. 70% of occupied homes are lived in by their owner (Texas: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Gonzales County | Texas |
|---|---|---|
| Housing units | 8,976 | 11,890,808 |
| Detached houses | 66% | 65% |
| In buildings of 5 or more | 2% | 21% |
| Mobile homes | 24% | 7% |
| Built before 1960 | 30% | 13% |
| Built since 2000 | 28% | 37% |
| Middle year built | 1982 | 1990 |
| Owner-occupied | 70% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.