Great Falls, MT Radon Mitigation and Testing

Q: What is the average radon level in Great Falls, MT?

Based on 3 user-submitted tests, the average radon level is 4.00 pCi/L.

Q: What EPA Radon Zone is Great Falls in?

Great Falls is in Cascade County, EPA Zone 1.

Q: How much does radon mitigation cost in Great Falls?

Radon mitigation typically costs between $800 and $2,000. Most standard systems fall in the $1,000-$1,500 range.

Avg: 4.00 pCi/L

Cascade County

EPA Zone 1

3 user tests

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.

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.

Great Falls, MT Radon Testing

Finding qualified radon testing professionals is the first step toward protecting your home.

Great Falls, Montana Radon Levels

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

Radon Level	City	Home Age	Foundation	Submitted
3 pCi/L	Great Falls, MT	51-99 Years	Full Basement	Apr 2022
6 pCi/L	Great Falls, MT	51-99 Years	Full Basement	Jul 2021

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

Great Falls Radon Facts

Key details about the radon risk profile for Great Falls and the 59401 zip code area.

EPA Radon Zone

Zone 1 — High Risk

County

Cascade County, MT

Zip Code

59401

Predicted Screening Level

> 4.0 pCi/L (Zone 1)

Avg. User Submitted Level

4.00 pCi/L

User Tests Submitted

Great Falls and the 59401 zip code are located in Cascade County, which has an EPA assigned Radon Zone of 1. A radon zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L. The EPA recommends testing every home regardless of zone classification.

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 with the most user-submitted radon test data in the state.

City	Avg User Radon Level	Submissions
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
Great Falls	4.50 pCi/L	2
Whitefish	4.00 pCi/L	2
Ennis	9.00 pCi/L	1
Livingston	No submissions	0