What a high radon result means
Radon is a naturally occurring radioactive gas that moves from soil into homes through slabs, cracks, sumps, and crawl spaces. Test results are reported in picocuries per liter, written pCi/L. The EPA's action level is 4 pCi/L. At or above that number the agency recommends reducing radon, and it suggests considering a fix at levels between 2 and 4 pCi/L. A high result is not an emergency, but it should not be ignored. Long-term exposure to elevated radon is associated with a higher risk of lung cancer, which is why the next steps matter.
Confirm the number before you design a fix
A single short-term test is a snapshot. Weather, window use, a recent storm, device placement, and test length can all shift the number. EPA guidance generally recommends a follow-up test when a first short-term result is at or above the action level. If the first result is well above 4 pCi/L, retest right away instead of waiting. A long-term test over several months can also give a better picture for an occupied home. See radon testing for how tests are chosen and winter radon testing for why closed-house conditions matter in Park City.
Gather the details of your test
- The report, device type, and test duration.
- The dates of the test and the weather during it.
- Where in the home the device was placed, such as a lower level or bedroom.
- Whether windows or doors were opened, and whether a fan or HVAC change occurred.
- Your foundation type: basement, crawl space, slab, or a mix.
How mitigation usually works
Most homes are fixed with active soil depressurization. A pipe is run from beneath the slab or a sealed crawl-space membrane to a point outside the living space, and a fan draws soil gas away before it enters the house. Openings are sealed to help the system work. The EPA reports that properly installed systems can reduce radon levels substantially. After installation, a new test confirms the result. See radon mitigation for the full process and crawl space radon mitigation if the home has a crawl space or mixed foundation.
Park City homes and system routing
Park City homes often have finished lower levels, steep lots, and HOA appearance rules that affect where a pipe and fan can go. Exterior routing, attic routing, and interior routing each have tradeoffs. Mentioning your neighborhood, HOA, and any architectural review requirements helps a provider quote the system correctly. Second homes and nightly rentals can be tested and mitigated like full-time residences, with scheduling built around access.
If you are buying or selling
Inspection periods are short, so a high result during a transaction is time-sensitive. Buyers may request a retest, a mitigation system, or a credit. Sellers often prefer to know the number early so a plan is in place. Keep the report and share your closing dates with the provider. The real estate radon page has more detail.
What mitigation costs and what changes the quote
Pricing depends on the foundation, access, pipe routing, fan location, finishes, and the number of suction points needed. A slab-on-grade home is different from one with a basement and a crawl space. The radon mitigation cost guide covers the main variables so you can compare quotes more carefully.
After the system is installed
A working fan should run continuously. Check the system's indicator now and then, retest on a regular schedule, and retest after remodels or foundation changes. The EPA suggests retesting at least every two years. If the fan makes noise or the indicator changes, see radon system repair. All radon work described through this site is performed by licensed, insured local professionals.
Frequently asked questions
- What radon level is considered high?
- The EPA recommends fixing a home when the radon level is 4 pCi/L or higher, and suggests considering a fix for levels between 2 and 4 pCi/L. Because no level is risk-free, the decision is also about your situation and timeline.
- Should I retest if my first result is high?
- Often yes. Short-term tests can vary with weather, ventilation, and where the device was placed. A second test, sometimes a long-term one, helps confirm the number before a system is designed. If the first result is far above 4 pCi/L, retest promptly.
- How long does radon mitigation take?
- Many standard systems can be installed in a day or so, but the timeline depends on the foundation, access, and routing of the pipe. A post-installation test follows to confirm the result.
- Can I sell or buy a Park City home with a high radon result?
- Yes. Radon is commonly addressed during a transaction through retesting, a mitigation system, or a negotiated credit. See real estate radon testing for how the timing usually works.