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 Rockwall County, Texas
EPA puts Rockwall County in Zone 3, its lowest radon zone, and only 16 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
8.7%
Dallas County
- Dallas
- 8.7%
- Collin
- 7.7%
2 of 4 neighbours have 30+ tests, 2007 to 2016
Nearest county
7.7%
Collin County, 22 miles
- Collin
- 7.7%
- Texas
- 10.4%
Share at 4+ pCi/L, 284 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
- Rockwall
- 0.0%
- Texas
- 27.3%
Share of land USGS rates moderate or high potential
Tests reported
16
Too few for a share
- Rockwall
- 16
- 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 Rockwall 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
Rockwall County, At a glance
Rockwall 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 Rockwall County, 2008 to 2017, laboratory
CDC holds 16 reported tests for Rockwall County over the 2008 to 2017 laboratory totals, with a median of 1.2 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Rockwall County beside the counties around it is how this page reads it.
What these figures count
Only 16 tests were reported to CDC for Rockwall 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).
Rockwall County, Compared
Rockwall County radon figures, compared
Calculated by Radon411CDC's largest figure for Rockwall County rests on 16 tests over the 2008 to 2017 laboratory totals, 3 of them at or above 4 pCi/L, so each test moves its share by 6.3 points and no rank or comparison is drawn from it. Results reached as high as 9.8 pCi/L, with a middle value of 1.2 pCi/L.
Of the counties bordering it, 2 have a figure over the 2007 to 2016 laboratory totals: Dallas County reported the largest share at or above 4 pCi/L, 8.7%, and Collin County the smallest, 7.7%. Farther out, Denton County (46 miles away) at 7.2%, Tarrant County (52 miles away) at 10.6% and Smith County (76 miles away) at 9.1% 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 Rockwall 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.
Rockwall County, Geology
The ground under Rockwall County
PredictedUSGS's geologic map puts all of Rockwall 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.
Rockwall County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Rockwall County's is. Of the 4 counties that border it, 2 have more moderate-potential ground, Dallas County the most at 64.8%.
The map rates the ground, not the air in any home.
Local help
Rockwall County, Local resources
Radon testing and mitigation in Rockwall 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.
Listed radon professionals by town: Dallas
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
Rockwall County, Questions
Questions about radon in Rockwall County
Are radon levels high in Rockwall County?
Over the 2008 to 2017 laboratory totals, 18.8% of the radon tests reported to CDC for Rockwall County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.2 pCi/L. Of the counties bordering it, 2 have a figure over the 2007 to 2016 laboratory totals: Dallas County reported the largest share at or above 4 pCi/L, 8.7%, and Collin County the smallest, 7.7%.
Which counties border Rockwall County?
Rockwall County borders 4 counties: Kaufman County, Collin County, Hunt County and Dallas County.
Products
Rockwall County, Products
Testing a home in Rockwall County
No CDC figure names Rockwall County; the nearest county with one, Collin County (22 miles away), reported 7.7% 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 Rockwall 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
RadonScan USB-powered radon monitor with a color screen
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
First reading: Within 5 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Rockwall County, Bordering counties
Counties bordering Rockwall County
Calculated by Radon411- Radon levels in Hunt CountyEPA zone 3
25.0%at or above 4 pCi/L
Median 2.0 pCi/L · 4 tests
- Radon levels in Dallas CountyEPA zone 3
8.7%at or above 4 pCi/L
Median 1.0 pCi/L · 699 tests
- Radon levels in Collin CountyEPA zone 3
7.7%at or above 4 pCi/L
Median 1.0 pCi/L · 284 tests
- Radon levels in Kaufman CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.3 pCi/L · 4 tests
Rockwall County, Cities and towns
Cities and towns in Rockwall County
Rockwall County is growing: the Census Bureau puts it at 140,738 residents on July 1, 2025, up 28.9% from 109,199 in 2020. Packed into its land, that is 1,106 people per square mile. Dallas, the largest place on its list (1,329,491 residents in all), extends beyond Rockwall County, so no share of the total is worked out for it. CDC's 16 reported tests for 2008 to 2017 work out to 0.1 per 1,000 residents (2025 estimate), close to Texas' 0.1.
From Dallas to Mobile City, CDC publishes no figure by town: each reads Rockwall County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Dallasextends beyond Rockwall County | 1,329,491 | +2.0% | Counted whole |
| Garlandextends beyond Rockwall County | 249,625 | +1.3% | Counted whole |
| Rowlettextends beyond Rockwall County | 67,890 | +8.2% | Counted whole |
| Wylieextends beyond Rockwall County | 63,842 | +10.3% | Counted whole |
| Rockwall | 53,980 | +13.1% | 38.4% |
| Fate | 29,007 | +57.4% | 20.6% |
| Royse Cityextends beyond Rockwall County | 28,307 | +105.4% | Counted whole |
| Heathextends beyond Rockwall County | 11,671 | +19.8% | Counted whole |
| McLendon-Chisholmextends beyond Rockwall County | 5,629 | +53.7% | Counted whole |
| Mobile City | 172 | +20.3% | 0.1% |
10 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 Rockwall County is counted whole, so it has no share.
Rockwall County, Homes
Homes in Rockwall County
Rockwall County is a place of houses on their own lots: 85% of its 41,426 homes are detached single-family houses, against 65% across Texas. Much of Rockwall County is recent building: 65% of its homes have gone up since 2000 and the middle year built is 2005, against 1990 for Texas. 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 | Rockwall County | Texas |
|---|---|---|
| Housing units | 41,426 | 11,890,808 |
| Detached houses | 85% | 65% |
| In buildings of 5 or more | 8% | 21% |
| Mobile homes | 3% | 7% |
| Built before 1960 | 1% | 13% |
| Built since 2000 | 65% | 37% |
| Middle year built | 2005 | 1990 |
| Owner-occupied | 83% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.