Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Richland County, Wisconsin
EPA puts Richland County in Zone 1, its highest radon zone, and 33.3% of its 48 reported radon tests (2023) 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
Share at 4+ pCi/L
33.3%
2.4 pts below WI
- Richland
- 33.3%
- Wisconsin
- 35.7%
48 tests, 2023
Median result
2.9pCi/L
Below action level
- Richland
- 2.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
48
60th of 69 by tests
- Richland
- 48
- Dane
- 2,887
Reported to CDC before any fix, 2023
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Wisconsin
46 of 69
Middle half
- Richland
- 33.3%
- Langlade
- 65.8%
By share, of 69 with 30+ tests
Read a result for Richland County
Starts at Richland County's median, 2.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.9 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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. Richland County's median reported result, 2023.
The data
Richland County, At a glance
Richland County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Richland County in
USGS geologic potential: High across 68% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Richland County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 13.8% |
| 2015 | 37.1% |
| 2016 | 45.5% |
| 2017 | 48.7% |
| 2019 | 47.7% |
| 2020 | 29.2% |
| 2021 | 39.7% |
| 2022 | 37.0% |
| 2023 | 33.3% |
2023: 33.3%. Across these years the share ran from 13.8% to 48.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 48 tests reported to CDC for Richland 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).
Richland County, Compared
Richland County radon figures, compared
Calculated by Radon411In Richland County, about 3 in 10 reported tests in 2023 (16 of 48) were at or above EPA's action level. Against the national pool of 33.4%, the gap is 0.1 points lower. Across 72 Wisconsin counties pooled together, 35.7% of tests reached that level, so Richland County runs 2.4 points below its state.
Of 5 neighbours with a figure, all 5 reported a larger share at or above 4 pCi/L; the spread is 41.1% (Sauk County) to 61.0% (Iowa County). By share, Richland County is 46th of 69 Wisconsin counties with 30 or more tests for the same period.
Year by year, 2015 opened at 37.1% and 2023 closed at 33.3% (down 3.8 points), with 2017 the high at 48.7%. Half the tests came in under 2.9 pCi/L and half over it; the single highest reached 21.1 pCi/L. Below the action level, 17 tests (35.4%) came in under 2 pCi/L, against 41.4% statewide, and 15 tests (31.3%) fell between 2 and 4, against 23.0% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 33.3% share point the same way here. USGS geology rates 68% of the county's land high radon potential.
The busiest year on file was 2021, with 58 tests reported; the quietest, 2020, had 24.
Richland CountyWisconsin, pooled
| Year | Tests | Richland County, at or above 4 pCi/L | Wisconsin, pooled |
|---|---|---|---|
| 2015 | 35 | 37.1% | 51.6% |
| 2016 | 33 | 45.5% | 45.2% |
| 2017 | 39 | 48.7% | 44.8% |
| 2019 | 44 | 47.7% | 42.9% |
| 2021 | 58 | 39.7% | 39.9% |
| 2022 | 46 | 37.0% | 42.9% |
| 2023 | 48 | 33.3% | 35.7% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Richland County, Geology
The ground under Richland County
PredictedUSGS's geologic map splits Richland County: 68.3% of its land is high radon potential and 31.7% moderate. The map puts 68.3% of Richland County in the area it calls Driftless Area and 31.7% in Driftless Area. USGS gives the first a radon index of 12, in the high band (12 to 17), and the second 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Driftless Area | Cambrian sandstone and Ordovician limestone and dolostone. | High | 12 | 68.3% |
| Driftless Area | Cambrian sandstone. | Moderate | 10 | 31.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Richland County beside the ground around it
Richland County has more high-potential ground than Wisconsin as a whole: 68.3% of its land against 34.8%. Of the 5 counties that border it, 4 have more high-potential ground, Crawford County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Richland County, Local resources
Radon testing and mitigation in Richland County
- Wisconsin's radon programWisconsin Department of Health ServicesWisconsin's radon program does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Wisconsin.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
We recommend starting with your regional Radon Information Center since many centers provide test kits for free or reduced cost, and often with laboratory fees covered.
- Compare kits
- Professionals in Wisconsin19 professionals are listed in Wisconsin.
What Wisconsin's program says
- Phone
- 1-888-569-7236
- DHSRadon@dhs.wisconsin.gov
- Licensing of radon professionals
The State of Wisconsin does not require contractors performing radon measurement or mitigation work to be state licensed or nationally certified.
What it means
Richland County, Questions
Questions about radon in Richland County
Are radon levels high in Richland County?
In 2023, 33.3% of the radon tests reported to CDC for Richland County, Wisconsin were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.9 pCi/L. Of 69 Wisconsin counties with 30 or more tests for the same period, 45 reported a higher share; pooled, the state comes to 35.7%.
Which counties border Richland County?
Richland County borders 5 counties: Crawford County, Vernon County, Iowa County, Sauk County and Grant County.
Products
Richland County, Products
Testing a home in Richland County
In Richland County, 33.3% of 48 tests reported to CDC in 2023 reached 4 pCi/L, against 35.7% pooled across Wisconsin. In Zone 1 the year-round level in Richland 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
MonitorX-Sense
XR0A-SR battery digital radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Richland County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Richland County
Explore
Richland County, Bordering counties
Counties bordering Richland County
Calculated by Radon411- Radon levels in Iowa CountyEPA zone 1
61.0%at or above 4 pCi/L
Median 4.8 pCi/L · 146 tests · 27.7 points above Richland County
- Radon levels in Crawford CountyEPA zone 1
53.9%at or above 4 pCi/L
Median 4.4 pCi/L · 217 tests · 20.6 points above Richland County
- Radon levels in Grant CountyEPA zone 1
48.3%at or above 4 pCi/L
Median 3.5 pCi/L · 323 tests · 15.0 points above Richland County
- Radon levels in Vernon CountyEPA zone 1
47.5%at or above 4 pCi/L
Median 3.8 pCi/L · 162 tests · 14.2 points above Richland County
- Radon levels in Sauk CountyEPA zone 2
41.1%at or above 4 pCi/L
Median 3.3 pCi/L · 241 tests · 7.8 points above Richland County
Richland County, Cities and towns
Cities and towns in Richland County
About 17,036 people live in Richland County by the Census Bureau's estimate for July 1, 2025, 245 fewer than in 2020 (−1.4%). That works out to 29 people per square mile of land. Its largest town, Richland Center, has 5,020 residents, 29.5% of the total. CDC's 48 reported tests for 2023 work out to 2.8 per 1,000 residents (2025 estimate), close to Wisconsin's 3.5.
From Richland Center to Yuba, CDC publishes no figure by town: each reads Richland County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Richland Center | 5,020 | −3.3% | 29.5% |
| Lone Rock | 828 | −0.6% | 4.9% |
| Violaextends beyond Richland County | 728 | +9.1% | Counted whole |
| Cazenoviaextends beyond Richland County | 350 | −3.3% | Counted whole |
| Boaz | 122 | −4.7% | 0.7% |
| Yuba | 51 | −1.9% | 0.3% |
6 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 Richland County is counted whole, so it has no share.
Richland County, Homes
Homes in Richland County
Richland County is a place of houses on their own lots: 81% of its 8,542 homes are detached single-family houses, against 66% across Wisconsin. Half of its homes were built before 1970, close to Wisconsin's 1975: 42% date from before 1960 and 16% from 2000 or later. Owners live in 76% of the occupied homes (Wisconsin: 68%), so for most households a test and a fix are their own to order.
| Homes | Richland County | Wisconsin |
|---|---|---|
| Housing units | 8,542 | 2,750,750 |
| Detached houses | 81% | 66% |
| In buildings of 5 or more | 6% | 17% |
| Mobile homes | 5% | 3% |
| Built before 1960 | 42% | 34% |
| Built since 2000 | 16% | 20% |
| Middle year built | 1970 | 1975 |
| Owner-occupied | 76% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.