
MonitorAEGTEST
HOUND-1011 rechargeable radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
Locations and reports
EPA puts Walworth County in Zone 1, its highest radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
The data
Walworth County, At a glance
Predicted: EPA radon zone
This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.
EPA predicts an average indoor
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Of 340 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 131 | 38.5% |
| 2 to 4 pCi/L | 80 | 23.5% |
| 4 pCi/L and above | 129 | 37.9% |
CDC publishes this figure only for counties here, so there is no state or national number to compare Walworth County, Wisconsin with.
Distribution of radon tests reported to CDC, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.
The figures at the top are for 2023: a percentage there is a share of radon tests reported to CDC for Walworth County in 2023, and a percentage in a view below is a share of the tests reported for the year or period it names. It is not a share of homes in Walworth County, and it is not a random sample: it counts only the tests people chose to run and that were reported.
CDC works out the shares and the median over pre-mitigation tests, counting a test not marked as before or after mitigation as one of them (340 for 2023). The median is the middle result of those tests, not of buildings. CDC also reports the number of buildings tested (231), a different count, so the two totals are not interchangeable.
Walworth County's own published CDC figures beside those of the counties that border it, for the same period.
Each figure is that county’s own published CDC figure for 2023, counting radon tests reported to CDC, not homes. Walworth County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. No published CDC figure for 2023: McHenry County, IL; Boone County, IL. Every Wisconsin county’s own figure is in the Wisconsin county table.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Radon Action Brief
National Radon Action MonthPre-sale
Save 64%Sale price: $8.99Price after the sale: $25Ends Jan 31Then $25Sale ends January 31, then $25
Local help
Walworth County, Local resources
Who tests and fixes radon in Walworth County: listed businesses, Wisconsin's radon program and test kits.
Listed radon businesses with an address in Walworth County:
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.
Listed radon professionals by town: Williams Bay, Genoa City
The State of Wisconsin does not require contractors performing radon measurement or mitigation work to be state licensed or nationally certified.
What it means
Walworth County, Questions
No listed mitigator names Walworth County as a service area yet; the Wisconsin directory lists 18 companies. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether Wisconsin requires one.
Radon mitigation: how it worksRadon mitigation costRadon mitigation systemsMitigators in Wisconsin
In 2023, 37.9% of the radon tests reported to CDC for Walworth County, Wisconsin were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.8 pCi/L. That is a share of reported tests, not of homes. EPA places Walworth County in Zone 1, highest predicted potential, a predicted average indoor screening level greater than 4 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.
Radon levels: what a result meansWhat is radon?Radon levels in Wisconsin
EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No radon testing business listed on Radon411 has an address in Walworth County or names it as a service area yet. The Wisconsin radon program is the place to ask about certified testers and any test kit offer it runs.
Radon testing: how to test a homeRadon test kits comparedFree and low-cost kits by stateRadon Action Month checklistWisconsin radon program
EPA places Walworth County, Wisconsin in Zone 1, which EPA describes as highest predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.
Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.
EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.
EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.
Walworth County borders 7 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.
The reported-test figures on this page describe Walworth County, Wisconsin in 2023. They describe tests other people carried out in other buildings, and none of them measures yours.
What the published data says about Walworth County, in words. A zone and a share of tests describe an area, never the level in any one home.
EPA places Walworth County in Zone 1, highest predicted potential, as it does 27 other counties of Wisconsin's 72.
Of the 7 bordering counties, EPA places Boone County, IL, Jefferson County, Rock County and Waukesha County in Zone 1 and Kenosha County, McHenry County, IL and Racine County in Zone 2.
CDC has annual figures for Walworth County for 9 years, 2014 to 2023. In 2023, 37.9% of 340 reported tests were at or above 4 pCi/L.
Across those years the share ranged from 37.9% (2023) to 59.5% (2015). Few tests in a year can move it a long way.
Wisconsin's radon program and its page are under Local resources.
The county's largest incorporated places are Whitewater, Burlington and Elkhorn; the figures here cover them as part of the county.
Products
Walworth County, Products
Whatever the figures for Walworth County show, only a test tells you about one home.
Test kits and monitors: 1 of 42
As an Amazon Associate, Radon411 earns from qualifying purchases.
Walworth County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Walworth County
Testing: 1 of 5
Mitigation: 1 of 3
Explore
Walworth County, Bordering counties
counties bordering Walworth County: 1 of 7
7 counties share a boundary with Walworth County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.
Walworth County, Cities and towns
The radon figures on this page are for Walworth County as a whole. They do not differ by city or town.
14 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. “(part)” marks a place that extends into another county.
Walworth County, Next steps
What to do next: 1 of 4
Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.