Radon levels in Fond du Lac County, Wisconsin
ModerateEPA Zone 1Predicted long-term basement average of 2.7 pCi/L (model estimate) across 14 ZIP codes - about 1.5× the US average of 1.8, about 1.3× the Wisconsin average of 2.0. Ranked #14 of 72 Wisconsin counties.
Test Fond du Lac County, WI - the EPA says "consider fixing" in this range
The predicted basement average here is 2.7 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.
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Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.
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Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. Measured state test results are shown separately below, labeled with their source and years. How the numbers work.
2.7 ± 0.08
pCi/L predicted basement mean (model SD)
1.8 ± 0.06
pCi/L predicted upstairs (above-ground) mean
2.1-3.0
range of ZIP-level basement predictions in the county
Measured radon tests in Fond du Lac County (Wisconsin Department of Health Services, 1995-2016)
Actual results from home radon tests reported to the state, separate from the model estimate above. Coverage: 1995-2016.
- Measured mean
- 6.5 pCi/L
- Results ≥ 4 pCi/L
- 55.7%
- Results ≥ 2 pCi/L
- 78.9%
- Sample
- 1,929 tests
| Figure | Model (predicted) | State tests (measured) |
|---|---|---|
| Mean, pCi/L | 2.7 basement | 6.5 |
| Share ≥ 4 pCi/L | not a model output | 55.7% |
The measured mean runs 3.8 pCi/L above the model because state test data is voluntary and skews toward basements, winter, and homeowners who already suspected a problem, while the model estimates the long-term average across all homes.
Source: Wisconsin Indoor Radon Test Results (Wisconsin Radon Map Service, layer 3), Wisconsin Department of Health Services. No license statement on the public feature service. Method and download.
Tested above 4 pCi/L? Get a mitigation quote from a certified local contractor
Typical mitigation runs $800-$2,500 and takes a day. Installers guarantee the system brings levels under 4 pCi/L. Tell us where you are in Fond du Lac County, WI and a certified mitigator will follow up - no obligation.
What this means for Fond du Lac
The typical Fond du Lac County home is predicted in the 2-4 pCi/L band. The EPA's guidance for this range is to consider fixing, because there is no known safe level and roughly one home in several in a moderate area will test above 4.
Note that the EPA classifies Fond du Lac County as Zone 1 while the newer model predicts 2.7 pCi/L. The zone map predates two decades of test data; where they disagree, we grade on the model but show both. County figures weight each ZIP by its 2010 Census population, so they describe where people live rather than empty land.
Comparable Wisconsin counties: Lincoln County (2.7), Waupaca County (2.7), Green Lake County (2.6), Richland County (2.6). The state's highest is Lafayette County at 3.4 pCi/L.
ZIP codes in Fond du Lac County
Predicted basement and upstairs means by ZIP (model estimate). ZIPs whose land is mostly in this county.
| ZIP | Basement | Upstairs | Grade |
|---|---|---|---|
| 54935 | 2.7 ± 0.09 | 1.7 | Moderate |
| 54937 | 2.7 ± 0.07 | 1.8 | Moderate |
| 53963 | 2.9 ± 0.09 | 2.1 | Moderate |
| 54971 | 2.6 ± 0.07 | 2.0 | Moderate |
| 53010 | 2.6 ± 0.07 | 1.9 | Moderate |
| 53919 | 3.0 ± 0.06 | 2.3 | Moderate |
| 53049 | 2.1 ± 0.06 | 1.3 | Moderate |
| 53065 | 2.9 ± 0.06 | 2.0 | Moderate |
| 53019 | 2.8 ± 0.06 | 2.0 | Moderate |
| 53057 | 2.7 ± 0.06 | 2.0 | Moderate |
| 54974 | 2.9 ± 0.06 | 2.0 | Moderate |
| 54979 | 2.1 ± 0.05 | 1.2 | Moderate |
| 53079 | 2.7 ± 0.06 | 2.0 | Moderate |
| 54932 | 2.9 ± 0.06 | 2.1 | Moderate |
If your test comes back at 4 pCi/L or higher
Mitigation is a routine job: a fan-driven pipe that vents soil gas from under the slab to above the roofline, typically $800-$2,500 installed (typical range; local quotes vary). Use certified professionals: EPA find-a-professional. Read the full mitigation guide.
Fond du Lac County radon questions
- Is radon high in Fond du Lac County, Wisconsin?
- Moderate. The model predicts a long-term basement average of 2.7 pCi/L in Fond du Lac County (about 1.5× the US average of 1.8 and about 1.3× the Wisconsin average of 2.0). That is in the 2-4 pCi/L range where the EPA recommends considering mitigation. Ranked 14 of 72 Wisconsin counties.
- What do actual radon tests show in Fond du Lac County?
- Wisconsin Department of Health Services data covering 1995-2016 (1,929 tests) shows an average of 6.5 pCi/L, 55.7% of results at or above the 4 pCi/L action level, 78.9% at or above 2. These are voluntary home tests, so they skew toward basements and toward homes where radon was suspected; the model's predicted long-term basement average for the county is 2.7 pCi/L.
- Should I test for radon in Fond du Lac County?
- Yes, soon. With a predicted average of 2.7 pCi/L, many homes in Fond du Lac County will test above the 4 pCi/L action level. Use a short-term kit first; if it reads 2 or higher, confirm with a long-term test or continuous monitor before deciding on mitigation.
- What does EPA Radon Zone 1 mean for Fond du Lac County?
- Zone 1 - highest potential (predicted average > 4 pCi/L). The zone map dates from 1993 and classifies whole counties. The newer model's predicted average of 2.7 pCi/L does not line up with Zone 1, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.
- How much does radon mitigation cost in Fond du Lac County?
- A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; Wisconsin quotes vary with foundation type (slab, crawlspace, basement), home size and local labor. Get two or three bids from certified mitigators listed by your state radon program or the EPA's find-a-professional page.
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