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Radon Levels in Gwinnett County, Georgia

EPA puts Gwinnett County in Zone 1, its highest radon zone, and 32.4% of its 4,187 reported radon tests (2008 to 2017, laboratory totals) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    32.4%

    7.6 pts above GA

    Gwinnett
    32.4%
    Georgia
    24.8%

    4,187 tests, 2008 to 2017

  • Median result

    2.7pCi/L

    Below action level

    Gwinnett
    2.7 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    4,187

    2nd of 57 by tests

    Gwinnett
    4,187
    Fulton
    4,858

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in Georgia

    18 of 57

    Middle half

    Gwinnett
    32.4%
    Barrow
    48.3%

    By share, of 57 with 30+ tests

Read a result for Gwinnett County

Starts at Gwinnett County's median, 2.7 pCi/L

2.7pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 2.7 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Gwinnett County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Gwinnett County, At a glance

Gwinnett County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Gwinnett County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Gwinnett County, 2008 to 2017, laboratory

Reported results by concentration band, Gwinnett County, 2008 to 2017, laboratory
Under 2 pCi/L: 33%2 to 4 pCi/L: 34%4 pCi/L and above: 33%

Of 4,187 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Gwinnett County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L1,39633.3%
2 to 4 pCi/L1,43534.3%
4 pCi/L and above1,35632.4%
What these figures count

These are the 4,187 tests reported to CDC for Gwinnett County over 2008 to 2017 (laboratory totals), many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.

Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Gwinnett County, Compared

Gwinnett County radon figures, compared

Calculated by Radon411

In Gwinnett County, about 3 in 10 reported tests over the 2008 to 2017 laboratory totals (1,356 of 4,187) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 3.3 points lower. Across 129 Georgia counties pooled together, 24.8% of tests reached that level, so Gwinnett County runs 7.6 points above its state.

Of 8 neighbours with a figure, 4 reported a larger share at or above 4 pCi/L and 4 a smaller one; the spread is 13.0% (Forsyth County) to 48.3% (Barrow County). By share, Gwinnett County is 18th of 57 Georgia counties with 30 or more tests for the same period.

Half the tests came in under 2.7 pCi/L and half over it; the single highest reached 61.1 pCi/L. Below the action level, 1,396 tests (33.3%) came in under 2 pCi/L, against 44.0% statewide, and 1,435 tests (34.3%) fell between 2 and 4, against 31.2% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 32.4% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 372 tests taken after mitigation in Gwinnett County for the same period: tests in homes where a fix was already in.

CDC's ten-year totals for Gwinnett County went from 3,539 tests (2005 to 2014) to 4,187 (2008 to 2017), the share going from 31.1% to 32.4%.

Gwinnett County against Georgia, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Gwinnett County
Gwinnett County4,18732.4%2.7 pCi/LThis county
Georgia, pooled129 counties, pooled30,15224.8%Not pooled−7.6 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+3.3 points
Douglas Countyhighest in the state35547.3%3.7 pCi/L+14.9 points
Richmond Countylowest in the state320.0%1.4 pCi/L−32.4 points
Barrow County, GAborders it32148.3%3.8 pCi/L+15.9 points
Walton County, GAborders it83042.2%3.3 pCi/L+9.8 points
Jackson County, GAborders it46040.0%3.2 pCi/L+7.6 points
Hall County, GAborders it1,30339.8%3.2 pCi/L+7.4 points
Rockdale County, GAborders it24729.1%2.3 pCi/L−3.3 points
Fulton County, GAborders it4,85820.8%2.2 pCi/L−11.6 points
DeKalb County, GAborders it3,47518.0%1.8 pCi/L−14.4 points
Forsyth County, GAborders it1,38313.0%1.9 pCi/L−19.4 points
Where Gwinnett County's reported results fell, 2008 to 2017, laboratory, beside Georgia and the United States
ResultGwinnett County testsGwinnett County shareGeorgia shareU.S. shareAgainst Georgia
Under 2 pCi/L1,39633.3%44.0%39.6%−10.7 points
2 to 4 pCi/L1,43534.3%31.2%24.7%+3.1 points
4 pCi/L and above1,35632.4%24.8%35.7%+7.6 points
Gwinnett County ranked among the 57 Georgia counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Habersham County13 of 5712837.5%3.1 pCi/L
Banks County14 of 575735.1%2.8 pCi/L
Troup County15 of 575633.9%2.9 pCi/L
Spalding County16 of 5710733.6%2.9 pCi/L
Oglethorpe County17 of 577332.9%2.5 pCi/L
Gwinnett County18 of 574,18732.4%2.7 pCi/L
Towns County19 of 5714431.9%2.8 pCi/L
Gordon County20 of 573531.4%2.1 pCi/L
Fayette County21 of 5787330.5%2.6 pCi/L
Putnam County22 of 573030.0%2.2 pCi/L
Rockdale County23 of 5724729.1%2.3 pCi/L
Gwinnett County ten-year laboratory totals, against Georgia's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestGeorgia, pooledChange from the row before
2008 to 20174,18732.4%2.7 pCi/L61.1 pCi/L24.8%+0.4 points
2007 to 20164,16932.0%2.7 pCi/L54.4 pCi/L23.9%Level
2006 to 20153,90732.0%2.7 pCi/L54.4 pCi/L23.7%+0.9 points
2005 to 20143,53931.1%2.6 pCi/L54.4 pCi/L23.2%First on file

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

Gwinnett County, Geology

The ground under Gwinnett County

Predicted

USGS's geologic map puts all of Gwinnett County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Georgiabama Thrust Stack (South), to which USGS gives a radon index of 9, in the moderate band (9 to 11).

USGS's geologic areas under Gwinnett County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Georgiabama Thrust Stack (South)Schist, amphibolite and granite.Moderate9100%

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

Gwinnett County beside the ground around it

Gwinnett County has more moderate-potential ground than Georgia as a whole: 100% of its land against 26.5%. Of the 8 counties that border it, none has as large a share of moderate-potential ground; Barrow County comes nearest at 100%.

Share of land by USGS radon potential: Gwinnett County, the 8 counties bordering it and Georgia
AreaEPA zoneLow potentialModerate potentialHigh potential
Gwinnett CountyZone 1None100%None
DeKalb CountyZone 1None100%None
Forsyth CountyZone 2None100%None
Barrow CountyZone 2None100%None
Rockdale CountyZone 2None100%None
Fulton CountyZone 1None100%None
Walton CountyZone 2None100%None
Hall CountyZone 2None100%None
Jackson CountyZone 2None100%None
Georgia159 counties, pooled by land areaVaries73.1%26.5%None

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

Local help

Gwinnett County, Local resources

Radon testing and mitigation in Gwinnett County

What Georgia's program says
Licensing of radon professionals
There are no laws mandating a mitigator receive certification in Georgia, however, many mitigators choose to get certified by one of two national programs.

What it means

Gwinnett County, Questions

Questions about radon in Gwinnett County

Are radon levels high in Gwinnett County?

Over the 2008 to 2017 laboratory totals, 32.4% of the radon tests reported to CDC for Gwinnett County, Georgia were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.7 pCi/L. Of 57 Georgia counties with 30 or more tests for the same period, 17 reported a higher share; pooled, the state comes to 24.8%.

Which counties border Gwinnett County?

Gwinnett County borders 8 counties: DeKalb County, Forsyth County, Barrow County, Rockdale County, Fulton County, Walton County, Hall County and Jackson County.

Products

Gwinnett County, Products

Testing a home in Gwinnett County

In Gwinnett County, 32.4% of 4,187 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 24.8% pooled across Georgia. In Zone 1 the year-round level in Gwinnett County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.

Test kits and monitors3

See every kit and monitor

Gwinnett County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Gwinnett County

Explore

Gwinnett County, Bordering counties

Counties bordering Gwinnett County

Calculated by Radon411

Gwinnett County, Cities and towns

Cities and towns in Gwinnett County

Gwinnett County is growing: the Census Bureau puts it at 1,018,099 residents on July 1, 2025, up 6.2% from 958,317 in 2020. Packed into its land, that is 2,364 people per square mile. No town dominates: Peachtree Corners, the largest, has 42,519 residents, 4.2% of the total. Testing is reported here more often than across the state: CDC's 4,187 reported tests for 2008 to 2017 come to 4.1 for every 1,000 residents (2025 estimate), against 2.7 for Georgia.

From Peachtree Corners to Rest Haven, CDC publishes no figure by town: each reads Gwinnett County's.

The 12 largest cities and towns in Gwinnett County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Peachtree Corners42,519+0.7%4.2%
Duluth33,815+4.9%3.3%
Lawrenceville32,822+7.5%3.2%
Sugar Hill29,280+16.5%2.9%
Suwanee23,034+9.8%2.3%
Snellville22,478+9.1%2.2%
Norcross19,086+8.8%1.9%
Bufordextends beyond Gwinnett County18,780+9.6%Counted whole
Braseltonextends beyond Gwinnett County18,496+35.9%Counted whole
Loganvilleextends beyond Gwinnett County17,212+20.9%Counted whole
Lilburn16,369+14.6%1.6%
Auburnextends beyond Gwinnett County10,110+33.7%Counted whole
  • Dacula
  • Grayson
  • Berkeley Lake
  • Rest Haven (part)

16 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Gwinnett County is counted whole, so it has no share.

Gwinnett County, Homes

Homes in Gwinnett County

Of Gwinnett County's 336,078 homes, 71% are detached houses, against 66% across Georgia; 18% are in buildings of five or more homes. Half of its homes were built before 1995, close to Georgia's 1991: 2% date from before 1960 and 39% from 2000 or later. 67% of occupied homes are lived in by their owner (Georgia: 65%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Gwinnett County, Georgia, 2019 to 2023
HomesGwinnett CountyGeorgia
Housing units336,0784,483,873
Detached houses71%66%
In buildings of 5 or more18%16%
Mobile homes2%8%
Built before 19602%12%
Built since 200039%33%
Middle year built19951991
Owner-occupied67%65%

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