Wisconsin — 1.6M metro

Radon in Milwaukee,
WI

Milwaukee County sits in EPA Zone 1, and Wisconsin's radon testing program consistently finds elevated levels across the metro area. Wisconsin's older housing stock makes Milwaukee one of the higher-risk major metros for radon exposure.

Risk Level

High Risk

2–7 pCi/L

Typical range (area avg.)

EPA action level: 4 pCi/L

Why Milwaukee Has High Risk Radon

Milwaukee sits on glacial lake plain deposits over Silurian dolomite. The Lake Michigan shore creates its own microclimate effects on radon, and the deep clay-rich lake sediments can concentrate radon in areas with poor foundation drainage.

Local Housing and Radon Risk

Milwaukee has one of the Midwest's oldest housing stocks, with many pre-1940 homes featuring stone foundations, dirt-floor crawlspaces, and unfinished basements in neighborhoods like Bay View, Riverwest, and Shorewood.

Testing Advice for Milwaukee Residents

Wisconsin DNR has a licensed radon contractor database. For Milwaukee's older homes with stone or brick foundations, get multiple contractor bids — mitigation complexity varies significantly with foundation type.

How to Test Your Milwaukee Home

Step 1: Choose Your Test Type

For initial screening, a charcoal short-term test kit ($12–$25) placed for 48–96 hours provides a quick result. For the most accurate reading, a long-term alpha-track test ($20–$35) left in place for 90+ days accounts for seasonal variation — especially important in Milwaukee's climate.

Step 2: Place the Test Correctly

Test in your lowest livable level — basement if you have one, otherwise the first floor. Keep the test 20 inches from the floor, away from windows and exterior walls. Close windows and doors 12 hours before and during the test for accurate results.

Step 3: Interpret Your Results

Below 2 pCi/L: low concern, retest every 2 years. 2–4 pCi/L: consider mitigation, retest in 2 years. 4 pCi/L or higher: the EPA recommends mitigation. Above 8 pCi/L: prioritize mitigation promptly.

Step 4: Hire a Certified Mitigator if Needed

If your test result is at or above 4 pCi/L, hire a certified radon mitigator. In Wisconsin, always verify your contractor's state certification. Sub-slab depressurization — the most effective mitigation method — typically costs $850–$1,500 installed in the Milwaukee area.

Frequently Asked Questions — Radon in Milwaukee

Is radon a real problem in Milwaukee?

Yes. Milwaukee County sits in EPA Zone 1, and Wisconsin's radon testing program consistently finds elevated levels across the metro area. Wisconsin's older housing stock makes Milwaukee one of the higher-risk major metros for radon exposure. The EPA recommends all homes be tested regardless of location — radon levels can vary significantly even between neighboring properties.

How much does radon mitigation cost in this area?

In the Milwaukee area, professional radon mitigation (sub-slab depressurization) typically costs $850–$1,500 installed. This is a one-time cost that reduces radon by 50–99%. The system requires minimal maintenance and a mitigator can typically complete the work in 3–5 hours.

Should I test if I have a new home?

Absolutely. New homes built with radon-resistant features still show elevated levels in testing — construction conditions and local geology vary too much to assume any home is safe. Test within the first year of occupancy, especially if your home has a basement.

Can I test radon myself, or do I need a professional?

DIY testing is reliable and recommended as a first step. Short-term kits ($12–$25) and long-term kits ($20–$35) are accurate when placed and returned correctly. Professional testing is only required for real estate transactions in some states. If your DIY test shows elevated levels, use a certified professional for both confirmation testing and mitigation.