Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Mills County, Texas
EPA puts Mills County in Zone 3, its lowest radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Nearest county
14.3%
Bell County, 73 miles
- Bell
- 14.3%
- Texas
- 10.4%
Share at 4+ pCi/L, 35 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
- Mills
- 0.0%
- Texas
- 27.3%
Share of land USGS rates moderate or high potential
Tests reported
0
None published
A home here needs its own test
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 Mills 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
Mills County, At a glance
Mills 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
No CDC test figures here
CDC has published no radon test figures for Mills County. Bell County, 73 miles away, is the nearest county with a figure over the 2007 to 2016 laboratory totals.
Mills County, Compared
Mills County radon figures, compared
Calculated by Radon411CDC's county radon counts over the 2007 to 2016 laboratory totals cover 140 Texas counties, and Mills County is not among them: no year's figure and no ten-year laboratory total names it. Pooled across 140 Texas counties, 10.4% of reported tests reached that level; across every county in the country with a figure, 35.8%.
The nearest counties with a figure are Bell County (73 miles away) at 14.3%, McLennan County (82 miles away) at 17.1% and Williamson County (83 miles away) at 2.0%. 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 Mills 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.
Mills County, Geology
The ground under Mills County
PredictedUSGS's geologic map puts all of Mills County's mapped land in one class: low radon potential. The map puts 73.6% of Mills County in the area it calls Central Texas/Gulf Coast Plain and 26.4% in Central Texas. USGS gives both 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 |
|---|---|---|---|---|
| Central Texas/Gulf Coast Plain | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 7 | 73.6% |
| Central Texas | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 7 | 26.4% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Mills County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Mills County's is. Of the 5 counties that border it, 2 have more moderate-potential ground, San Saba County the most at 47.9%.
The map rates the ground, not the air in any home.
Local help
Mills County, Local resources
Radon testing and mitigation in Mills 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
Mills County, Questions
Questions about radon in Mills County
Are radon levels high in Mills County?
No CDC testing statistics are published here for Mills County, Texas yet. Of the 8 nearest counties with a figure, within 146 miles, the share of tests at or above 4 pCi/L runs from 2.0% to 17.1%.
Which counties border Mills County?
Mills County borders 5 counties: San Saba County, Lampasas County, Comanche County, Brown County and Hamilton County.
Products
Mills County, Products
Testing a home in Mills County
No CDC figure names Mills County; the nearest county with one, Bell County (73 miles away), reported 14.3% 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 Mills 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
RM-63Pro rechargeable radon monitor with a touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Mills County, Bordering counties
Counties bordering Mills County
Calculated by Radon411- Radon levels in Brown CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 1.8 pCi/L · 1 test
- Radon levels in Hamilton CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
- Radon levels in San Saba CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in Lampasas CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in Comanche CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Mills County, Cities and towns
Cities and towns in Mills County
The Census Bureau estimates 4,580 residents in Mills County for July 1, 2025, 133 more than in 2020 (+3.0%). Spread over its land, that is 6.1 people to the square mile. Its largest town, Goldthwaite, has 1,774 residents, 38.7% of the total. Together its 2 incorporated places hold 41.6% of those residents; the other 58.4% live outside any of them. CDC publishes no radon test count for Mills County; across Texas its counts for 2007 to 2016 come to 0.1 tests for every 1,000 residents (2025 estimate).
From Goldthwaite to Mullin, CDC publishes no figure by town: each reads Mills County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Goldthwaite | 1,774 | +2.7% | 38.7% |
| Mullin | 130 | +2.4% | 2.8% |
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).
Mills County, Homes
Homes in Mills County
Mills County is a place of houses on their own lots: 82% of its 2,614 homes are detached single-family houses, against 65% across Texas. The homes are older than Texas' as a whole: half were built before 1977 (1990 for Texas), and 29% date from before 1960. Owners live in 84% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.
| Homes | Mills County | Texas |
|---|---|---|
| Housing units | 2,614 | 11,890,808 |
| Detached houses | 82% | 65% |
| In buildings of 5 or more | under 1% | 21% |
| Mobile homes | 13% | 7% |
| Built before 1960 | 29% | 13% |
| Built since 2000 | 20% | 37% |
| Middle year built | 1977 | 1990 |
| Owner-occupied | 84% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.