Radon mitigation
If your radon test result is 200 Bq/m3 or higher, take action to reduce radon levels in your home or building.
Health Canada recommends reducing radon levels below the Canadian Guideline of 200 Bq/m3 within 1 year. The higher the radon level, the sooner action should be taken.
Reducing radon exposure can lower long-term health risks for building occupants.
On this page
- Find a certified mitigation professional
- Questions to ask before hiring a professional
- Common radon reduction measures
- These measures may not be effective in all situations. A certified mitigation professional can recommend the best approach for your building. Test again after mitigation.
- Additional resources
Find a certified mitigation professional
Many buildings require specialized work to effectively reduce radon levels.
A professional certified through the Canadian National Radon Proficiency Program (C-NRPP) can:
- review your radon test results
- identify how radon is entering the building
- recommend mitigation options
- confirm whether additional testing is needed
You may need to work with a professional from another province or territory if no certified mitigation professional is available in the Northwest Territories.
Find a certified radon mitigation professional
When searching for a certified professional look for:
- residential mitigation, or
- commercial mitigation
Questions to ask before hiring a professional
Before hiring a mitigation professional, consider asking:
- How many radon mitigation projects have you completed?
- Have you worked on buildings similar to mine?
- Can you provide proof of C-NRPP certification?
- Will you inspect my building before providing an estimate?
- Will you explain the proposed work and expected results?
- Will you test the building to help determine the most effective mitigation approach?
- Will you include a warning device if the mitigation system stops working properly?
- Do you provide a performance guarantee?
Common radon reduction measures
The most effective mitigation method depends on the building and how radon is entering it.
Possible mitigation measures include:
- fitting an airtight cover to an open sump
- sealing visible cracks and openings in floors and walls
- maintaining traps in floor drains
- covering exposed crawlspace soil with a sealed membrane
- improving ventilation in specific areas of the building
These measures may not be effective in all situations. A certified mitigation professional can recommend the best approach for your building. Test again after mitigation.
After mitigation work is complete, test again to confirm that radon levels have been reduced below the Canadian Guideline of 200 Bq/m3,
For the most reliable results:
- test during the colder months when windows and doors are usually closed
- use a C-NRPP-approved long-term radon test
- leave the detector in place for at least 91 days (3 months)
Long-term testing provides the most accurate picture of radon levels over time.