Radon in Dakota County
Why the MDH flags most Dakota County homes above the EPA action level.
Why the MDH flags most Dakota County homes above the EPA action level. This field guide is written for Lakeville and Twin Cities south-metro homeowners by Home Inspector Lakeville MN.
Radon is the leading cause of lung cancer in non-smokers, and Dakota County is a high-radon area. The Minnesota Department of Health reports that the majority of homes tested in this region come back above the EPA action level of 4.0 pCi/L. For Lakeville buyers, radon measurement is not optional caution — it is baseline diligence.
Why our geology drives it
Radon is a soil gas. It enters through foundation cracks, sumps, and slab penetrations and accumulates in the lower levels of a closed-up house — exactly the conditions of a Minnesota winter. The local soils and bedrock release enough radon that even newer, tight homes routinely test high.
How it is measured
An EPA-protocol continuous monitor runs a minimum of 48 hours under closed-house conditions. Continuous monitoring resists tampering and shows the hour-by-hour pattern, which is more trustworthy than a single passive canister for a real estate transaction.
What to do about a high result
Mitigation — typically a sub-slab depressurization system installed by a certified contractor — is highly effective and well understood. A high radon result is not a deal-breaker; it is a fixable, negotiable item. The deal-breaker is not testing at all.
Why even new homes test high here
It is a common misconception that radon is an old-house problem. It is a soil-gas problem. A brand-new, tightly built Lakeville home sitting on the same Dakota County soil can — and often does — test above the action level, because the tight envelope holds the gas in. New construction is not a reason to skip the test.
Mitigation is routine and effective
Sub-slab depressurization, installed by a certified contractor, reliably brings levels down and is a well-understood, code-recognized system. A high result is a negotiation item with a known fix — never a reason to abandon a house you otherwise want.
Keep reading
All buyer-education articles · Knowledge center · Full home inspection
Know the house
before you own it.
Same-week availability · Photo-mapped digital report in 24 hours · 952-583-3701