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Radon Levels in Franklin County, Texas

EPA puts Franklin County in Zone 3, its lowest radon zone, and only 1 radon test from it is on file with CDC (2006 to 2015, laboratory totals). 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

    9.1%

    Smith County, 55 miles

    Smith
    9.1%
    Texas
    10.4%

    Share at 4+ pCi/L, 33 tests, 2007 to 2016

  • Ground above low

    None

    27.3 pts below Texas

    Franklin
    0.0%
    Texas
    27.3%

    Share of land USGS rates moderate or high potential

  • Tests reported

    1

    Too few for a share

    Franklin
    1
    Needed
    30

    2006 to 2015, laboratory

  • 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 Franklin 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

Franklin County, At a glance

Franklin County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Franklin 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 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Franklin County, 2006 to 2015, laboratory

CDC holds 1 reported test for Franklin County over the 2006 to 2015 laboratory totals, a result of 0.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Franklin County beside the counties around it is how this page reads it.

What these figures count

Only 1 test was reported to CDC for Franklin County over 2006 to 2015 (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: 2006 to 2015, laboratory. Measured data period: 2005 to 2015 (every CDC figure on file).

How to read these figures

Franklin County, Compared

Franklin County radon figures, compared

Calculated by Radon411

CDC's largest figure for Franklin County rests on 1 test over the 2006 to 2015 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 0.1 pCi/L, with a middle value of 0.1 pCi/L.

The nearest counties with a figure are Smith County (55 miles away) at 9.1%, Collin County (78 miles away) at 7.7% and Dallas County (95 miles away) at 8.7%. 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 Franklin 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.

Texas, the United States and the counties around Franklin 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
Hopkins County, TXborders it1100.0%5.0 pCi/L
Titus County, TXborders it10.0%0.1 pCi/L
The nearest Texas counties to Franklin County with 30 or more tests, 2007 to 2016, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Smith County55 mi339.1%0.8 pCi/L
Collin County78 mi2847.7%1.0 pCi/L
Dallas County95 mi6998.7%1.0 pCi/L
Denton County110 mi1817.2%0.9 pCi/L
Tarrant County124 mi31210.6%0.9 pCi/L
McLennan County161 mi4117.1%1.0 pCi/L
Brazos County185 mi490.0%0.2 pCi/L
Bell County198 mi3514.3%1.1 pCi/L
Franklin County ten-year laboratory totals, against Texas' pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestTexas, pooledChange from the row before
2006 to 201510.0%0.1 pCi/L0.1 pCi/L11.0%Level
2005 to 201410.0%0.1 pCi/L0.1 pCi/L10.6%First on file

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

Franklin County, Geology

The ground under Franklin County

Predicted

USGS's geologic map puts all of Franklin 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).

USGS's geologic areas under Franklin County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
East Texas ProvinceCretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite.Low6100%

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

Franklin County beside the ground around it

Across Texas 0.5% of the land is rated high; none of Franklin County's is. Of the 6 counties that border it, 1 has more moderate-potential ground, Red River County the most at 20.6%.

Share of land by USGS radon potential: Franklin County, the 6 counties bordering it and Texas
AreaEPA zoneLow potentialModerate potentialHigh potential
Franklin CountyZone 3100%NoneNone
Titus CountyZone 3100%NoneNone
Camp CountyZone 3100%NoneNone
Hopkins CountyZone 3100%NoneNone
Red River CountyZone 379.4%20.6%None
Wood CountyZone 3100%NoneNone
Delta CountyZone 3100%NoneNone
Texas254 counties, pooled by land areaVaries72.4%26.8%0.5%

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

Local help

Franklin County, Local resources

Radon testing and mitigation in Franklin 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

Franklin County, Questions

Questions about radon in Franklin County

Are radon levels high in Franklin County?

Over the 2006 to 2015 laboratory totals, 0.0% of the radon tests reported to CDC for Franklin 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 198 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 17.1%.

Which counties border Franklin County?

Franklin County borders 6 counties: Titus County, Camp County, Hopkins County, Red River County, Wood County and Delta County.

Products

Franklin County, Products

Testing a home in Franklin County

No CDC figure names Franklin County; the nearest county with one, Smith County (55 miles away), reported 9.1% 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 Franklin County.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Franklin County homes, compared

Explore

Franklin County, Bordering counties

Counties bordering Franklin County

Calculated by Radon411

Franklin County, Cities and towns

Cities and towns in Franklin County

Franklin County is growing: the Census Bureau puts it at 10,994 residents on July 1, 2025, up 6.0% from 10,372 in 2020. That works out to 39 people per square mile of land. Winnsboro, the largest place on its list (3,678 residents in all), extends beyond Franklin County, so no share of the total is worked out for it. CDC's 1 reported test for 2006 to 2015 work out to 0.1 per 1,000 residents (2025 estimate), close to Texas' 0.1.

From Winnsboro to Mount Vernon, CDC publishes no figure by town: each reads Franklin County's.

The cities and towns in Franklin County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Winnsboroextends beyond Franklin County3,678+6.5%Counted whole
Mount Vernon2,610+4.7%23.7%

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). A place that extends beyond Franklin County is counted whole, so it has no share.

Franklin County, Homes

Homes in Franklin County

Franklin County is a place of houses on their own lots: 82% of its 5,121 homes are detached single-family houses, against 65% across Texas. Half of its homes were built before 1989, close to Texas' 1990: 12% date from before 1960 and 29% from 2000 or later. Owners live in 79% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.

Homes in Franklin County, Texas, 2019 to 2023
HomesFranklin CountyTexas
Housing units5,12111,890,808
Detached houses82%65%
In buildings of 5 or more3%21%
Mobile homes11%7%
Built before 196012%13%
Built since 200029%37%
Middle year built19891990
Owner-occupied79%63%

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