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Radon in Mankato, Minnesota

Mankato lies in 3 counties, in EPA Zone 1; 98.1% of it is in Blue Earth County, where 32.7% of 392 reported tests (2023) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so the only way to know your home's level is to test it.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    32.7%

    1.9 pts below MN

    Blue Earth
    32.7%
    Minnesota
    34.6%

    Blue Earth, 48th of 62 in MN, 2023

  • Median result

    2.2pCi/L

    Below action level

    Blue Earth
    2.2 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of Blue Earth's tests, 2023

  • Highest county

    62.2%

    Le Sueur

    Le Sueur
    62.2%
    Blue Earth
    32.7%

    3 counties, 3 with 30+ tests, 2023

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    Blue Earth; Nicollet Zone 1, Le Sueur Zone 1

  • Tests reported

    392

    In Blue Earth

    Blue Earth
    392
    Le Sueur
    135

    Reported to CDC before any fix, 2023

Read a result for Mankato

Starts at Blue Earth County's median, 2.2 pCi/L

2.2pCi/L

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

EPA’s reading of 2.2 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. Blue Earth County's median reported result, 2023.

Interpret this readingWhat a fix costs

The data

Mankato, What is published

What is published for Mankato

Information:

Every figure for Mankato is a county's

Radon data is published by county, not by city, and Mankato reaches into 3 counties: Blue Earth County, Nicollet County and Le Sueur County. Each has its own EPA zone and its own CDC test figures, set side by side below and each labelled with its county. Only a test tells you about one home.

Mankato covers 19.3 square miles of land across 3 counties: 98.1% in Blue Earth County, 1.8% in Nicollet County and 0.1% in Le Sueur County. About 46,529 people live there, 2,411 to the square mile.

Mankato, Counties

Mankato's counties, side by side

Measured

Each county's own EPA zone and its own published CDC figures for 2023, the newest period any of them has. A county without a figure for that period is shown without one, never with a figure from another year.

  • Blue Earth County
    EPA zone
    Zone 1: Highest predicted potential
    At or above 4 pCi/L
    32.7%
    Median result
    2.2 pCi/L
    Tests reported
    392 tests
    Annual years on file
    10
  • Nicollet County
    EPA zone
    Zone 1: Highest predicted potential
    At or above 4 pCi/L
    45.7%
    Median result
    3.7 pCi/L
    Tests reported
    129 tests
    Annual years on file
    10
  • Le Sueur County
    EPA zone
    Zone 1: Highest predicted potential
    At or above 4 pCi/L
    62.2%
    Median result
    5.1 pCi/L
    Tests reported
    135 tests
    Annual years on file
    10
The counties Mankato lies in, each with its own EPA zone and its own published CDC figures for 2023
CountyEPA zoneReported tests at or above 4 pCi/LMedian reported resultTests reportedAnnual years on file
Blue Earth CountyZone 1: Highest predicted potential32.7%2.2 pCi/L392 tests10
Nicollet CountyZone 1: Highest predicted potential45.7%3.7 pCi/L129 tests10
Le Sueur CountyZone 1: Highest predicted potential62.2%5.1 pCi/L135 tests10

Mankato spans 3 counties, each with its own EPA zone and its own CDC figure: Blue Earth County (Zone 1, 32.7% of 392 tests), Nicollet County (Zone 1, 45.7% of 129 tests) and Le Sueur County (Zone 1, 62.2% of 135 tests).

Blue Earth County ranks 48th of 62 Minnesota counties with 30 or more tests for that period, 1.9 points below the 34.6% pooled across Minnesota's counties, 0.7 points below the national pool of 33.4%. Of the city's other counties, Nicollet County reported 45.7% and Le Sueur County reported 62.2%.

Measured from the middle of Mankato, the nearest counties with a CDC figure for 2023 are Waseca County (22 miles, 60.3% of 63 tests), Sibley County (31 miles, 60.0% of 55 tests) and Faribault County (34 miles, 70.0% of 30 tests). Across the 8 nearest, the share at or above 4 pCi/L runs from 40.4% to 70.0%; the farthest of them, Martin County, is 45 miles away at 43.2%.

The directory lists 2 businesses with an address in Mankato, 2 for testing and 1 for mitigation. Minnesota's other cities with a page of their own: Minneapolis, St. Paul, Plymouth and St. Cloud.

Against Minnesota and its other counties

Radon test figures for the counties Mankato lies in
CountyShare of MankatoTestsAt or above 4 pCi/LMedianMinnesota, pooledRank in the stateEPA zone
Blue Earth County98.1%39232.7%2.2 pCi/L34.6%48 of 62Zone 1
Nicollet County1.8%12945.7%3.7 pCi/L34.6%30 of 62Zone 1
Le Sueur County0.1%13562.2%5.1 pCi/L34.6%10 of 62Zone 1

Shares of tests people chose to run and report, by county (2023); the state's is its counties' counts added up, calculated by Radon411. Only a test measures a home.

The counties around Mankato

By distance from the middle of Mankato; counties with 30 or more tests.

Nearest counties to Mankato with 30 or more tests
CountyDistanceTestsAt or above 4 pCi/LMedian
Waseca County22 mi6360.3%5.0 pCi/L
Sibley County31 mi5560.0%5.0 pCi/L
Faribault County34 mi3070.0%8.1 pCi/L
Rice County36 mi29740.4%3.2 pCi/L
Brown County38 mi11563.5%5.4 pCi/L
Steele County39 mi14051.4%4.0 pCi/L
Scott County40 mi66941.4%3.4 pCi/L
Martin County45 mi8143.2%3.5 pCi/L

The median reported pre-mitigation result for 2023 was 2.2 pCi/L in Blue Earth County, 3.7 pCi/L in Nicollet County and 5.1 pCi/L in Le Sueur County.

Predicted: EPA Map of Radon Zones, by county. Measured: CDC tracking data, by county, 2023.

Mankato, Geology

The ground under Mankato

Predicted

USGS's geologic map puts all of Mankato's mapped land in one class: high radon potential. The map puts 59.9% of Mankato in the area it calls Glacial Lake Deposits and 40.1% in Central Lowland-Till Prairie. USGS gives both a radon index of 14, in the high band (12 to 17).

USGS's geologic areas under Mankato
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Glacial Lake DepositsSilt and clay glacial lake deposits.High1459.9%
Central Lowland-Till PrairieSilty and clayey till derived from shale and sandstone.High1440.1%

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

Mankato beside its counties and Minnesota

All of Mankato, like all of Blue Earth County, is rated high. Mankato has more high-potential ground than Minnesota as a whole: 100% of its land against 61.1%.

Share of land by USGS radon potential: Mankato, the counties it lies in and Minnesota
AreaEPA zoneLow potentialModerate potentialHigh potential
MankatoBy countyNoneNone100%
Blue Earth CountyZone 1NoneNone100%
Nicollet CountyZone 1NoneNone100%
Le Sueur CountyZone 1NoneNone100%
Minnesota87 counties, pooled by land areaVariesNone38.9%61.1%

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

Mankato, Homes

Homes in Mankato

Mankato has 19,186 homes, and many share a building: 33% are in buildings of five or more, 45% are detached houses, against 59% across Blue Earth County. Half of its homes were built before 1981, close to Blue Earth County's 1977: 29% date from before 1960 and 32% from 2000 or later. 50% of occupied homes are lived in by their owner (Blue Earth County: 62%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Mankato, Blue Earth County, Minnesota, 2019 to 2023
HomesMankatoBlue Earth CountyMinnesota
Housing units19,18629,5442,519,538
Detached houses45%59%66%
In buildings of 5 or more33%23%19%
Mobile homes5%4%3%
Built before 196029%33%29%
Built since 200032%28%22%
Middle year built198119771978
Owner-occupied50%62%72%

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

Local help

Mankato, Professionals

Radon professionals listed in Mankato

Businesses whose listed city is Mankato, from the state registries and listings in the Radon411 directory, with the same business and certification status the directory shows.

2 listings with Mankato as the city. See radon mitigation and testing in Mankato, or all radon professionals in Minnesota.

Mankato, Local resources

Local resources for Mankato

Who to ask in Minnesota: its radon program, test kits and professionals.

The program's own words on licensing and disclosure are on the Minnesota page.

What it means

Mankato, Questions

Questions about radon in Mankato

What radon zone is Mankato in?

All 3 counties Mankato reaches into (Blue Earth County, Nicollet County and Le Sueur County) are in Zone 1, the map's highest class: a predicted county average above 4 pCi/L. EPA zones counties, not cities, so that is the zone for every part of Mankato.

What are radon levels in Mankato?

Around Mankato, 32.7% of 392 tests reported from Blue Earth County for 2023 reached 4 pCi/L or more, so a high result is no surprise here. The median reported result was 2.2 pCi/L. Nicollet County reported 45.7% of 129 tests and Le Sueur County reported 62.2% of 135 tests; the counties are kept apart.

Should I test my home in Mankato?

Yes. Blue Earth County reported about 128 of its 392 tests at or above 4 pCi/L. That is about what Minnesota as a whole reports (34.6%), and ranks Blue Earth County 48th of the 62 Minnesota counties with 30 or more tests. Which homes they were, no map can say. How to test a home.

What ground is Mankato built on, as far as radon goes?

59.9% of Mankato sits on what USGS's map calls "Glacial Lake Deposits", rated high for radon potential, radon index 14; another 40.1% is "Central Lowland-Till Prairie", in the same class.

Is radon higher in the counties around Mankato?

Higher, in every direction measured: all 8 of the nearest counties with a figure report a larger share of high tests than Blue Earth County's 32.7%, up to Faribault County (70.0%, 34 miles off).

Who tests for or fixes radon in Mankato?

Mankato is the address of 2 businesses in Radon411's directory, 2 listed for testing and 1 for mitigation. Each entry names the public list it came from. Radon professionals in Mankato.

The answers use the published figures of Blue Earth County, Nicollet County and Le Sueur County, the counties Mankato lies in.

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