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Radon Levels in Lake County, Indiana

EPA puts Lake County in Zone 2, its middle radon zone, and 23.5% of its 1,198 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

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  • Share at 4+ pCi/L

    23.5%

    15.4 pts below IN

    Lake
    23.5%
    Indiana
    38.9%

    1,198 tests, 2008 to 2017

  • Median result

    1.8pCi/L

    Below action level

    Lake
    1.8 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    1,198

    11th of 69 by tests

    Lake
    1,198
    St. Joseph
    7,346

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Indiana

    67 of 69

    Lowest quarter

    Lake
    23.5%
    Miami
    63.3%

    By share, of 69 with 30+ tests

Read a result for Lake County

Starts at Lake County's median, 1.8 pCi/L

1.8pCi/L

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

EPA’s reading of 1.8 pCi/L

Below 2 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 below 2 pCi/L, the level at which EPA says a fix should be considered. Lake County's median reported result, 2008 to 2017.

Interpret this reading

The data

Lake County, At a glance

Lake County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Lake County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 99% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

Reported results by concentration band, Lake County, 2008 to 2017, laboratory
Under 2 pCi/L: 52%2 to 4 pCi/L: 25%4 pCi/L and above: 23%

Of 1,198 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Lake County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L62251.9%
2 to 4 pCi/L29524.6%
4 pCi/L and above28123.5%
What these figures count

These are the 1,198 tests reported to CDC for Lake 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

Lake County, Compared

Lake County radon figures, compared

Calculated by Radon411

Lake County's 1,198 reported tests over the 2008 to 2017 laboratory totals had a middle value of 1.8 pCi/L and a maximum of 47.5 pCi/L, and 23.5% reached 4 pCi/L. Indiana as a whole (92 Indiana counties, pooled) comes to 38.9%: 15.4 points higher than here.

Among its state's counties it ranks 67th of 69 Indiana counties with 30 or more tests for the same period. Statewide for the same period, Miami County reported the highest share (63.3%) and Jasper County the lowest (14.1%).

Below the action level, 622 tests (51.9%) came in under 2 pCi/L, against 32.8% statewide, and 295 tests (24.6%) fell between 2 and 4, against 28.3% statewide. CDC's ten-year totals for Lake County went from 817 tests (2005 to 2014) to 1,198 (2008 to 2017), the share going from 19.5% to 23.5%.

EPA's 1993 zone map puts Lake County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 99% of the county's land moderate radon potential.

Next door, the shares run from 14.1% in Jasper County to 46.5% in Porter County, with Cook County, IL and Jasper County below Lake County.

CDC also counts 64 tests taken after mitigation in Lake County for the same period: tests in homes where a fix was already in.

Lake County against Indiana, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Lake County
Lake County1,19823.5%1.8 pCi/LThis county
Indiana, pooled92 counties, pooled43,14838.9%Not pooled+15.4 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+12.2 points
Miami Countyhighest in the state3063.3%5.3 pCi/L+39.8 points
Warrick Countylowest in the state56120.9%1.8 pCi/L−2.6 points
Porter County, INborders it1,13646.5%3.5 pCi/L+23.0 points
Will County, ILborders it5,57843.4%3.4 pCi/L+19.9 points
Kankakee County, ILborders it37942.5%3.3 pCi/L+19.0 points
Cook County, ILborders it14,19920.2%1.8 pCi/L−3.3 points
Jasper County, INborders it7114.1%1.2 pCi/L−9.4 points
Newton County, INborders it1612.5%1.6 pCi/L−11.0 points
Where Lake County's reported results fell, 2008 to 2017, laboratory, beside Indiana and the United States
ResultLake County testsLake County shareIndiana shareU.S. shareAgainst Indiana
Under 2 pCi/L62251.9%32.8%39.6%+19.1 points
2 to 4 pCi/L29524.6%28.3%24.7%−3.7 points
4 pCi/L and above28123.5%38.9%35.7%−15.4 points
Lake County ranked among the 69 Indiana counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Decatur County59 of 696333.3%2.8 pCi/L
Greene County60 of 694932.7%3.0 pCi/L
Dearborn County61 of 6913630.1%2.6 pCi/L
St. Joseph County62 of 697,34629.3%2.7 pCi/L
Franklin County63 of 695028.0%2.1 pCi/L
Jackson County64 of 698827.3%2.8 pCi/L
Brown County65 of 6911225.9%2.8 pCi/L
Vanderburgh County66 of 691,50524.4%2.4 pCi/L
Lake County67 of 691,19823.5%1.8 pCi/L
Warrick County68 of 6956120.9%1.8 pCi/L
Jasper County69 of 697114.1%1.2 pCi/L
Lake County ten-year laboratory totals, against Indiana's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIndiana, pooledChange from the row before
2008 to 20171,19823.5%1.8 pCi/L47.5 pCi/L38.9%+0.6 points
2007 to 20161,02822.9%1.8 pCi/L23.3 pCi/L39.2%+1.0 points
2006 to 201590821.9%1.8 pCi/L23.3 pCi/L39.6%+2.4 points
2005 to 201481719.5%1.6 pCi/L23.3 pCi/L39.3%First on file

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

Lake County, Geology

The ground under Lake County

Predicted

USGS's geologic map puts all of Lake County's mapped land in one class: moderate radon potential. The map puts 83.9% of Lake County in the area it calls Calumet Lacustrine Plain/Valparaiso Morainal Area and 15.3% in Kankakee Outwash and Lacustrine Plain. USGS gives the first a radon index of 11 and the second 10, both in the moderate band (9 to 11).

USGS's geologic areas under Lake County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Calumet Lacustrine Plain/Valparaiso Morainal AreaSilty to clayey glacial lake deposits and sand dunes.Moderate1183.9%
Kankakee Outwash and Lacustrine PlainMoraine deposits, outwash and dune sands.Moderate1015.3%

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

Lake County beside the ground around it

Across Indiana 56.6% of the land is rated high; none of Lake County's is. Of the 6 counties that border it, 5 have more high-potential ground, Kankakee County, IL the most at 62.9%.

Share of land by USGS radon potential: Lake County, the 6 counties bordering it and Indiana
AreaEPA zoneLow potentialModerate potentialHigh potential
Lake CountyZone 2None99.3%None
Porter CountyZone 2None99.8%None
Will County, ILZone 2None40.2%59.8%
Jasper CountyZone 2None46.0%54.0%
Newton CountyZone 2None50.9%49.1%
Kankakee County, ILZone 2None37.1%62.9%
Cook County, ILZone 2None96.8%3.2%
Indiana92 counties, pooled by land areaVariesNone43.4%56.6%

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

Local help

Lake County, Local resources

Radon testing and mitigation in Lake County

Listed radon businesses with an address in Lake County:

Listed radon professionals by town: Crown Point, Highland, Cedar Lake

What Indiana's program says
Phone
1-800-272-9723
Licensing of radon professionals
According to the Indiana Radon Rule, 410 IAC 5.1, everyone who is serving Indiana by doing radon testing, analysis and mitigation (radon reduction) in residential structures must be certified by the Indiana State Department of Health.

What it means

Lake County, Questions

Questions about radon in Lake County

Are radon levels high in Lake County?

Over the 2008 to 2017 laboratory totals, 23.5% of the radon tests reported to CDC for Lake County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.8 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 66 reported a higher share; pooled, the state comes to 38.9%.

Which counties border Lake County?

Lake County borders 6 counties: Porter County, IN, Will County, IL, Jasper County, IN, Newton County, IN, Kankakee County, IL and Cook County, IL.

Products

Lake County, Products

Testing a home in Lake County

In Lake County, 23.5% of 1,198 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 38.9% pooled across Indiana. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Lake County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Lake County homes, compared

Explore

Lake County, Bordering counties

Counties bordering Lake County

Calculated by Radon411

Lake County, Cities and towns

Cities and towns in Lake County

The Census Bureau estimates 504,612 residents in Lake County for July 1, 2025, 5,669 more than in 2020 (+1.1%). Packed into its land, that is 1,012 people per square mile. No town dominates: Hammond, the largest, has 75,712 residents, 15.0% of the total. Together its 19 incorporated places hold 91.6% of those residents; the other 8.4% live outside any of them. Reported testing is thin here: 1,198 tests over 2008 to 2017, or 2.4 for every 1,000 residents (2025 estimate), where Indiana as a whole comes to 6.2.

From Hammond to Schneider, CDC publishes no figure by town: each reads Lake County's.

The 12 largest cities and towns in Lake County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Hammond75,712−2.6%15.0%
Gary67,289−2.4%13.3%
Merrillville37,407+2.6%7.4%
Crown Point35,616+4.8%7.1%
Schererville29,825+0.5%5.9%
Hobart29,298−1.4%5.8%
East Chicago25,610−2.8%5.1%
St. John24,841+21.2%4.9%
Munster23,504−1.6%4.7%
Highland23,409−2.3%4.6%
Cedar Lake16,789+18.2%3.3%
Dyer16,273−1.3%3.2%
  • Griffith
  • Lake Station
  • Lowell
  • Winfield
  • Whiting
  • New Chicago
  • Schneider

19 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).

Lake County, Homes

Homes in Lake County

Of Lake County's 216,330 homes, 71% are detached houses, against 73% across Indiana; 13% are in buildings of five or more homes. The homes are older than Indiana's as a whole: half were built before 1968 (1976 for Indiana), and 40% date from before 1960. 71% of occupied homes are lived in by their owner (Indiana: 70%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Lake County, Indiana, 2019 to 2023
HomesLake CountyIndiana
Housing units216,3302,953,344
Detached houses71%73%
In buildings of 5 or more13%13%
Mobile homes1%4%
Built before 196040%32%
Built since 200017%21%
Middle year built19681976
Owner-occupied71%70%

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