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Radon Levels in Sterling County, Texas

EPA puts Sterling 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

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  • Nearest county

    1.0%

    Midland County, 58 miles

    Midland
    1.0%
    Texas
    10.4%

    Share at 4+ pCi/L, 100 tests, 2007 to 2016

  • Ground above low

    48.5%

    21.2 pts above Texas

    Sterling
    48.5%
    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. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

Read a result for Sterling County

Starts at EPA's action level

4.0pCi/L

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

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 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.

Interpret this readingWhat a fix costs

The data

Sterling County, At a glance

Sterling County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Sterling County as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

USGS geologic potential: Low across 51% 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 Sterling County. Midland County, 58 miles away, is the nearest county with a figure over the 2007 to 2016 laboratory totals.

How to read these figures

Sterling County, Compared

Sterling County radon figures, compared

Calculated by Radon411

CDC's county radon counts over the 2007 to 2016 laboratory totals cover 140 Texas counties, and Sterling 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 Midland County (58 miles away) at 1.0%, Lubbock County (131 miles away) at 57.8% and Bell County (218 miles away) at 14.3%. 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 Sterling County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 51% of the county's land low radon potential.

Texas, the United States and the counties around Sterling County, 2007 to 2016, laboratory
AreaTestsAt or above 4 pCi/LMedian
Texas, pooled140 counties, pooled4,54810.4%Not pooled
United States, pooled2,666 counties, pooled1,939,02535.8%Not pooled
Randall Countyhighest in the state8471.4%6.2 pCi/L
Nueces Countylowest in the state450.0%0.6 pCi/L
Tom Green County, TXborders it633.3%2.0 pCi/L
Howard County, TXborders it30.0%0.5 pCi/L
The nearest Texas counties to Sterling County with 30 or more tests, 2007 to 2016, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Midland County58 mi1001.0%0.7 pCi/L
Lubbock County131 mi12857.8%4.8 pCi/L
Bell County218 mi3514.3%1.1 pCi/L
Travis County219 mi4089.3%0.8 pCi/L
Williamson County220 mi982.0%0.7 pCi/L
Randall County222 mi8471.4%6.2 pCi/L
Bexar County223 mi1976.6%0.6 pCi/L
McLennan County227 mi4117.1%1.0 pCi/L

Pooled shares: Radon411's sum of CDC's county counts for one period.

Sterling County, Geology

The ground under Sterling County

Predicted

USGS's geologic map splits Sterling County: 51.5% of its land is low radon potential and 48.5% moderate. The map puts 48.5% of Sterling County in the area it calls Northern High Plains and Plateaus and 39.3% in Southern High Plains and Plateaus, with one smaller area beside them. USGS gives the first a radon index of 10, in the moderate band (9 to 11), and the second 7, in the low band (5 to 8).

USGS's geologic areas under Sterling County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Northern High Plains and PlateausTertiary sandstone, siltstone, shale.Moderate1048.5%
Southern High Plains and PlateausPaleozoic and Mesozoic sandstone, limestone, shale.Low739.3%
Central TexasCretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite.Low712.2%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Sterling County beside the ground around it

Across Texas 0.5% of the land is rated high; none of Sterling County's is. Of the 6 counties that border it, 3 have more moderate-potential ground, Glasscock County the most at 84.0%.

Share of land by USGS radon potential: Sterling County, the 6 counties bordering it and Texas
AreaEPA zoneLow potentialModerate potentialHigh potential
Sterling CountyZone 351.5%48.5%None
Glasscock CountyZone 316.0%84.0%None
Mitchell CountyZone 338.5%61.5%None
Coke CountyZone 3100%NoneNone
Howard CountyZone 355.9%44.1%None
Reagan CountyZone 332.8%67.2%None
Tom Green CountyZone 399.9%0.1%None
Texas254 counties, pooled by land areaVaries72.4%26.8%0.5%

The map rates the ground, not the air in any home.

Local help

Sterling County, Local resources

Radon testing and mitigation in Sterling County

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

Sterling County, Questions

Questions about radon in Sterling County

Are radon levels high in Sterling County?

No CDC testing statistics are published here for Sterling County, Texas yet. Of the 8 nearest counties with a figure, within 227 miles, the share of tests at or above 4 pCi/L runs from 1.0% to 71.4%.

Which counties border Sterling County?

Sterling County borders 6 counties: Glasscock County, Mitchell County, Coke County, Howard County, Reagan County and Tom Green County.

Products

Sterling County, Products

Testing a home in Sterling County

No CDC figure names Sterling County; the nearest county with one, Midland County (58 miles away), reported 1.0% 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 Sterling County.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Sterling County homes, compared

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Sterling County, Bordering counties

Counties bordering Sterling County

Calculated by Radon411

Sterling County, Cities and towns

Cities and towns in Sterling County

About 1,349 people live in Sterling County by the Census Bureau's estimate for July 1, 2025, 34 fewer than in 2020 (−2.5%). Spread over its land, that is 1.5 people to the square mile. Sterling City, its one incorporated place, has 1,094 residents, 81.1% of the total. CDC publishes no radon test count for Sterling County; across Texas its counts for 2007 to 2016 come to 0.1 tests for every 1,000 residents (2025 estimate).

Sterling City is the one incorporated place here; CDC publishes no figure by town, so it reads Sterling County's.

Sterling City, Sterling County: residents on July 1, 2025
PlaceResidentsSince 2020Share of residents
Sterling City1,094−2.3%81.1%

One incorporated place, 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).

Sterling County, Homes

Homes in Sterling County

Sterling County is a place of houses on their own lots: 77% of its 508 homes are detached single-family houses, against 65% across Texas. Half of its homes were built before 1985, close to Texas' 1990: 18% date from before 1960 and 19% from 2000 or later. Owners live in 83% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.

Homes in Sterling County, Texas, 2019 to 2023
HomesSterling CountyTexas
Housing units50811,890,808
Detached houses77%65%
In buildings of 5 or more0%21%
Mobile homes21%7%
Built before 196018%13%
Built since 200019%37%
Middle year built19851990
Owner-occupied83%63%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.