Radon Testing in Rochester, MN
Home Inspectors Rochester MN | Radon Testing (507) 721-0922
Rochester, Minnesota sits squarely in EPA Radon Zone 1, the highest-risk designation in the country. This means the average indoor radon level in Olmsted County is predicted to exceed 4 pCi/L — the EPA's recommended action level. If you own or are purchasing a home in Rochester or anywhere in Southeast Minnesota, professional radon testing is not optional. It is essential for protecting your family's health.
What Is Radon and Why Is It Dangerous?
Radon is an invisible, odorless, radioactive gas that forms naturally from the decay of uranium in soil, rock, and groundwater. It seeps into homes through cracks in foundations, gaps around pipes, sump pits, and any opening where the home contacts the ground. Once trapped indoors, radon accumulates to dangerous concentrations.
According to the EPA, radon is the second leading cause of lung cancer in the United States, responsible for an estimated 21,000 deaths per year. Only smoking causes more lung cancer deaths. The risk increases significantly with prolonged exposure to elevated radon levels, which is why testing the home where you spend the most time is so critical.
Why Rochester and Southeast Minnesota Have High Radon Levels
Southeast Minnesota's geology makes it particularly susceptible to high radon concentrations. The region sits on limestone and karst bedrock — a porous geological formation riddled with fractures, sinkholes, and underground channels. This karst geology allows radon gas to travel easily through the soil and into buildings above. Unlike clay-heavy soils that can partially block radon migration, the fractured limestone beneath Rochester provides a direct pathway from deep underground to your home's foundation.
Olmsted County consistently ranks among the highest radon areas in Minnesota. The Minnesota Department of Health reports that approximately two out of every five Minnesota homes have radon levels above the EPA action level, and the rate is even higher in our region. Whether your home is brand new or decades old, whether it has a basement or a slab-on-grade foundation, radon can be present at dangerous levels.
How Radon Testing Works
Professional radon testing provides the most accurate and reliable results. We use continuous radon monitors (CRMs) that measure radon levels every hour over a minimum 48-hour testing period. Unlike passive charcoal canisters, continuous monitors provide hour-by-hour data, detect any tampering or interference, and account for natural fluctuations in radon levels throughout the day.
During testing, the monitor is placed in the lowest livable level of the home, typically the basement or lowest floor. Windows and exterior doors should remain closed as much as possible during the test period, except for normal entry and exit. Once the test is complete, we analyze the results and provide you with a detailed report that includes the average radon concentration and hourly readings.
When Should You Test for Radon?
The EPA and Minnesota Department of Health recommend testing in the following situations:
- Every home purchase — radon testing should be part of every real estate transaction in Rochester. Levels can vary dramatically from one house to the next, even between neighboring homes.
- Every 2 years — if you have not tested your home recently, it is time. Radon levels change over time due to settling foundations, changes in soil moisture, and other factors.
- After major renovations — any work that alters your home's foundation, ventilation, or air sealing can change radon entry points and indoor concentrations.
- After installing a mitigation system — post-mitigation testing confirms the system is working effectively and radon levels are below the action threshold.
Understanding Radon Levels and the EPA Action Level
Radon is measured in picocuries per liter (pCi/L). The EPA has established 4.0 pCi/L as the action level — the concentration at which homeowners should take steps to reduce radon. However, the EPA also states that there is no safe level of radon exposure, and homeowners should consider mitigation even at levels between 2 and 4 pCi/L. The average outdoor radon concentration is approximately 0.4 pCi/L, and the average indoor level nationwide is about 1.3 pCi/L. In Rochester, indoor levels frequently test well above these national averages.
Radon Mitigation: What Happens If Levels Are High?
If your radon test results come back at or above 4 pCi/L, we recommend installing a radon mitigation system. The most common and effective method is sub-slab depressurization, which involves inserting a pipe through the basement floor into the gravel or soil beneath the slab. A fan connected to the pipe creates negative pressure below the foundation, drawing radon gas out before it enters the home and venting it safely above the roofline.
Professional mitigation systems typically reduce radon levels by 80% to 99%. After installation, a follow-up radon test confirms that levels have dropped below the EPA action level. We can guide you through the entire process, from initial testing through mitigation recommendations and post-mitigation verification.
Why Choose Our Radon Testing Services?
As experienced home inspectors in Rochester, MN, we understand the unique challenges that Southeast Minnesota's geology presents. Our radon testing services use calibrated, professional-grade continuous monitors for the most accurate results. We provide clear, detailed reports with actionable recommendations. Whether you are buying a home, selling a home, or simply want to ensure your family is safe, we are here to help.
Radon testing pairs well with our moisture inspection services, since many of the same foundation entry points that allow radon also permit moisture intrusion. For a comprehensive understanding of your home's indoor environment, consider adding a home energy audit to evaluate your home's air sealing and ventilation.
Protect your family from radon exposure.
Call (507) 721-0922 to schedule your radon test today.