Kentucky — 1.4M metro

Radon in Louisville,
KY

Kentucky has significant radon risk in its central and northern counties. Jefferson County (Louisville) falls in EPA Zone 2, with Kentucky's radon program reporting 20–25% of tested homes exceeding the action level across the metro area.

Risk Level

Moderate Risk

1–5 pCi/L

Typical range (area avg.)

EPA action level: 4 pCi/L

Why Louisville Has Moderate Risk Radon

Louisville sits on the edge of the Cincinnati Arch — a regional uplift of Ordovician limestone and shale. The underlying geology contains moderate uranium concentrations, and the Ohio River valley creates unique pressure dynamics affecting radon behavior.

Local Housing and Radon Risk

Louisville has extensive post-war housing in the Highlands, St. Matthews, and Jeffersontown areas. Older neighborhoods near the Ohio River often have homes with stone or concrete block basements that can accumulate radon more readily than poured concrete foundations.

Testing Advice for Louisville Residents

Kentucky Radon Program provides $10 testing kits at health departments. Louisville Metro's Jefferson County Health Department has local radon resources. Winter months (when homes are sealed) are best for accurate radon testing.

How to Test Your Louisville 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 Louisville'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 Kentucky, always verify your contractor's state certification. Sub-slab depressurization — the most effective mitigation method — typically costs $800–$1,400 installed in the Louisville area.

Frequently Asked Questions — Radon in Louisville

Is radon a real problem in Louisville?

Yes. Kentucky has significant radon risk in its central and northern counties. Jefferson County (Louisville) falls in EPA Zone 2, with Kentucky's radon program reporting 20–25% of tested homes exceeding the action level across the metro area. 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 Louisville area, professional radon mitigation (sub-slab depressurization) typically costs $800–$1,400 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.