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Great Falls, MT Radon Levels

Check local Great Falls radon levels and find certified testing and mitigation professionals to keep your home safe


Great Falls, MT Radon Facts

EPA Radon Zone Zone 1 — High Risk > 4.0 pCi/L (Zone 1)
County Cascade County, MT
Zip Code 59401
Avg. User Level 4.00 pCi/L
User Tests 3

Located in Cascade County along Montana's central plains, Great Falls experiences moderate radon levels averaging 4.5 pCi/L. While this reading slightly exceeds the EPA's 4.0 pCi/L threshold, the difference is minimal and many homes may still fall within acceptable ranges. Homeowners across zip codes 59401, 59404, and 59405 should conduct radon testing to determine their specific exposure levels, particularly in basement-level living areas.

4.00
pCi/L average
Above EPA Action Level

Based on 3 user-submitted radon tests for homes in Great Falls, MT. The EPA recommends taking action at or above 4.0 pCi/L.

0
4.0 EPA
10+

Great Falls, MT Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

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Great Falls, MT Radon Levels

User-submitted radon test readings from homes in the Great Falls area.

Radon LevelCityHome AgeFoundation
3 pCi/L Great Falls, MT 51-99 Years Full Basement
6 pCi/L Great Falls, MT 51-99 Years Full Basement

Have a radon test result for Great Falls? Submit your reading to help other homeowners.

Radon FAQ for Great Falls, MT

What is the average radon level in Great Falls, MT?
Based on 3 user-submitted tests, the average radon level in Great Falls is 4.00 pCi/L. This exceeds the EPA's recommended action level of 4.0 pCi/L, and radon testing is recommended for all homes in the area.
What EPA Radon Zone is Great Falls in?
Great Falls and the 59401 zip code are in Cascade County, which has an EPA assigned Radon Zone of 1. A zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L.
How much does radon mitigation cost in Great Falls?
Radon mitigation in Great Falls typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.
Should I test for radon if I'm buying a home in Great Falls?
Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.

Most Active Radon Markets in Montana

Cities in Montana with the most user-submitted radon test data, ranked by number of submissions.

CityAvg User Radon LevelSubmissions
Butte 10.20 pCi/L 10
Missoula 6.25 pCi/L 8
Florence 11.67 pCi/L 3
Bozeman 10.33 pCi/L 3
Helena 8.67 pCi/L 3
Stevensville 7.67 pCi/L 3
Sidney 7.33 pCi/L 3
Billings 5.33 pCi/L 3
Miles City 3.33 pCi/L 3
Kalispell 7.50 pCi/L 2