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Radon Levels in Richardson County, Nebraska

EPA puts Richardson County in Zone 1, its highest radon zone, and high results are common there: 61.8% of the 34 radon tests reported to CDC (2023) came back 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

    61.8%

    23.6 pts above NE

    Richardson
    61.8%
    Nebraska
    38.2%

    34 tests, 2023

  • Median result

    5.1pCi/L

    Action level reached

    Richardson
    5.1 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    34

    31st of 33 by tests

    Richardson
    34
    Lancaster
    4,058

    Reported to CDC before any fix, 2023

  • 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 Nebraska

    18 of 33

    Middle half

    Richardson
    61.8%
    Gage
    79.8%

    By share, of 33 with 30+ tests

Read a result for Richardson County

Starts at Richardson County's median, 5.1 pCi/L

5.1pCi/L

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

EPA’s reading of 5.1 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. Richardson County's median reported result, 2023.

Interpret this readingWhat a fix costs

The data

Richardson County, At a glance

Richardson County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Richardson 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: High across 96% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Richardson County, 2023

Share of reported tests at or above 4 pCi/L, by year, Richardson County
Share of reported tests at or above 4 pCi/L, by year, Richardson County
YearShare of reported tests at or above 4 pCi/L
201448.0%
201568.6%
201672.6%
201762.7%
201871.7%
201959.6%
202056.3%
202136.6%
202256.3%
202361.8%

2023: 61.8%. Across these years the share ran from 36.6% to 72.6%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 34 tests reported to CDC for Richardson County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Richardson County, Compared

Richardson County radon figures, compared

Calculated by Radon411

More than half: 61.8% of the 34 radon tests reported to CDC for Richardson County in 2023 read at least 4 pCi/L. That places it 18th of 33 Nebraska counties with 30 or more tests for the same period. That is 23.6 points above the 38.2% pooled from 86 Nebraska counties.

The median result, 5.1 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 47.2 pCi/L. The rest split 23.5% under 2 pCi/L and 14.7% from 2 to 4 (Nebraska: 39.2% and 22.6%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 61.8% share point the same way here.

Nemaha County, the one bordering county with a figure for the same period, reported 59.4%. Statewide for the same period, Gage County reported the highest share (79.8%) and Dakota County the lowest (3.1%).

The busiest year on file was 2016, with 405 tests reported; the quietest, 2022, had 16.

Over 9 years of annual figures the share rose 13.8 points, from 48.0% in 2014 to 61.8% in 2023; its peak was 72.6% in 2016. Nationally, every county with a figure for the same period pools to 33.4%; Richardson County sits 28.4 points above it. CDC also counts 8 tests taken after mitigation in Richardson County for the same period: tests in homes where a fix was already in.

Share of reported tests at or above 4 pCi/L by year, Richardson County against Nebraska2014 to 2023, years with 30 or more tests: Richardson County 48.0% to 61.8%, the state's pooled share 38.2% in 2023.
Richardson CountyNebraska, pooled
Share of reported tests at or above 4 pCi/L by year, Richardson County against Nebraska: data table
YearTestsRichardson County, at or above 4 pCi/LNebraska, pooled
201415048.0%50.5%
201515368.6%53.3%
201640572.6%47.4%
201720162.7%47.7%
201815971.7%44.5%
201914159.6%44.3%
20209656.3%42.2%
202140236.6%34.9%
20233461.8%38.2%
Richardson County against Nebraska, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Richardson County
Richardson County3461.8%5.1 pCi/LThis county
Nebraska, pooled86 counties, pooled11,16338.2%Not pooled−23.6 points
United States, pooled642 counties, pooled128,74033.4%Not pooled−28.4 points
Gage Countyhighest in the state8479.8%9.4 pCi/L+18.0 points
Dakota Countylowest in the state1303.1%0.4 pCi/L−58.7 points
Holt County, MOborders it1100.0%8.2 pCi/L+38.2 points
Nemaha County, NEborders it3259.4%5.7 pCi/L−2.4 points
Pawnee County, NEborders it450.0%5.1 pCi/L−11.8 points
Where Richardson County's reported results fell, 2023, beside Nebraska and the United States
ResultRichardson County testsRichardson County shareNebraska shareU.S. shareAgainst Nebraska
Under 2 pCi/L823.5%39.2%41.4%−15.7 points
2 to 4 pCi/L514.7%22.6%25.2%−7.9 points
4 pCi/L and above2161.8%38.2%33.4%+23.6 points
Richardson County ranked among the 33 Nebraska counties with 30 or more tests, by share at or above 4 pCi/L, 2023
CountyRankTestsAt or above 4 pCi/LMedian
Hamilton County13 of 334864.6%5.0 pCi/L
York County14 of 336264.5%5.7 pCi/L
Otoe County15 of 335964.4%5.7 pCi/L
Red Willow County16 of 335362.3%4.6 pCi/L
Dodge County17 of 3311662.1%5.0 pCi/L
Richardson County18 of 333461.8%5.1 pCi/L
Knox County19 of 334660.9%4.7 pCi/L
Nemaha County20 of 333259.4%5.7 pCi/L
Pierce County21 of 335556.4%5.0 pCi/L
Buffalo County22 of 3317355.5%4.2 pCi/L
Sarpy County23 of 3375551.9%4.1 pCi/L
Richardson County radon tests by year, against Nebraska's pooled share
YearTestsAt or above 4 pCi/LMedianHighestNebraska, pooledChange from the row before
20233461.8%5.1 pCi/L47.2 pCi/L38.2%+5.5 points
20221656.3%4.3 pCi/L13.6 pCi/L34.0%+19.7 points
202140236.6%2.9 pCi/L23.4 pCi/L34.9%−19.7 points
20209656.3%4.3 pCi/L11.0 pCi/L42.2%−3.3 points
201914159.6%5.4 pCi/L32.2 pCi/L44.3%−12.1 points
201815971.7%6.5 pCi/L31.9 pCi/L44.5%+9.0 points
201720162.7%5.1 pCi/L25.7 pCi/L47.7%−9.9 points
201640572.6%5.9 pCi/L34.4 pCi/L47.4%+4.0 points
201515368.6%6.9 pCi/L44.7 pCi/L53.3%+20.6 points
201415048.0%3.8 pCi/L35.5 pCi/L50.5%First on file

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

Richardson County, Geology

The ground under Richardson County

Predicted

Most of the ground under Richardson County is one class on USGS's geologic map: 96.2% of its land is high radon potential, with 3.8% moderate. 95.8% of it lies in the area the map calls Pre-Wisconsin glacial deposits, to which USGS gives a radon index of 13, in the high band (12 to 17).

USGS's geologic areas under Richardson County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Pre-Wisconsin glacial depositsLoess-mantled glacial drift.High1395.8%
Glaciated AreaGlacial till underlain by Pennsylvanian and Permian marine and nonmarine sedimentary shale, sandstone, limestone, coal.Moderate93.8%

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

Richardson County beside the ground around it

Richardson County has more high-potential ground than Nebraska as a whole: 96.2% of its land against 40.9%. Of the 6 counties that border it, 4 have more high-potential ground, Doniphan County, KS the most at 100%.

Share of land by USGS radon potential: Richardson County, the 6 counties bordering it and Nebraska
AreaEPA zoneLow potentialModerate potentialHigh potential
Richardson CountyZone 1None3.8%96.2%
Nemaha CountyZone 1NoneNone100%
Brown County, KSZone 1None7.5%92.5%
Holt County, MOZone 1NoneNone100%
Nemaha County, KSZone 1None16.6%83.4%
Pawnee CountyZone 1None1.3%98.7%
Doniphan County, KSZone 2NoneNone100%
Nebraska93 counties, pooled by land areaVaries28.2%30.9%40.9%

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

Local help

Richardson County, Local resources

Radon testing and mitigation in Richardson County

Listed radon businesses with an address in Richardson County:

Listed radon professionals by town: Humboldt

What Nebraska's program says
Phone
(402) 471-1005
Licensing of radon professionals
If radon testing is done in schools, offices, or other places of work, it must be done by a licensed radon measurement business.

What it means

Richardson County, Questions

Questions about radon in Richardson County

Are radon levels high in Richardson County?

In 2023, 61.8% of the radon tests reported to CDC for Richardson County, Nebraska were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.1 pCi/L. Of 33 Nebraska counties with 30 or more tests for the same period, 17 reported a higher share; pooled, the state comes to 38.2%.

Which counties border Richardson County?

Richardson County borders 6 counties: Nemaha County, NE, Brown County, KS, Holt County, MO, Nemaha County, KS, Pawnee County, NE and Doniphan County, KS.

Products

Richardson County, Products

Testing a home in Richardson County

In Richardson County, 61.8% of 34 tests reported to CDC in 2023 reached 4 pCi/L, against 38.2% pooled across Nebraska. In Zone 1 the year-round level in Richardson 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

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

Explore

Richardson County, Bordering counties

Counties bordering Richardson County

Calculated by Radon411

Richardson County, Cities and towns

Cities and towns in Richardson County

About 7,530 people live in Richardson County by the Census Bureau's estimate for July 1, 2025, 332 fewer than in 2020 (−4.2%). That works out to 14 people per square mile of land. Falls City alone is home to 3,988 of them, 53.0% of the total. CDC's 34 reported tests for 2023 work out to 4.5 per 1,000 residents (2025 estimate), close to Nebraska's 5.5.

From Falls City to Preston, CDC publishes no figure by town: each reads Richardson County's.

The 9 largest cities and towns in Richardson County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Falls City3,988−3.5%53.0%
Humboldt768−4.1%10.2%
Verdon156−4.3%2.1%
Shubert152−6.2%2.0%
Rulo145−0.7%1.9%
Stella140−6.0%1.9%
Dawson137−4.9%1.8%
Salem80−4.8%1.1%
Barada19−5.0%0.3%
  • Preston

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).

Richardson County, Homes

Homes in Richardson County

Richardson County is a place of houses on their own lots: 90% of its 4,084 homes are detached single-family houses, against 72% across Nebraska. The homes are older than Nebraska's as a whole: half were built before 1945 (1975 for Nebraska), and 63% date from before 1960. 75% of occupied homes are lived in by their owner (Nebraska: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Richardson County, Nebraska, 2019 to 2023
HomesRichardson CountyNebraska
Housing units4,084855,631
Detached houses90%72%
In buildings of 5 or more3%17%
Mobile homes2%3%
Built before 196063%32%
Built since 20005%22%
Middle year built19451975
Owner-occupied75%67%

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