Winthrop, WA Radon Mitigation and Testing

Q: What is the average radon level in Winthrop, WA?

Based on 3 user-submitted tests, the average radon level is 16.00 pCi/L.

Q: What EPA Radon Zone is Winthrop in?

Winthrop is in Okanogan County, EPA Zone 1.

Q: How much does radon mitigation cost in Winthrop?

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

Avg: 16.00 pCi/L

Okanogan County

EPA Zone 1

3 user tests

Tucked in the North Cascades of Okanogan County, Winthrop sits on mountainous terrain with granite and metamorphic bedrock that can generate significant radon levels. Local testing data shows an average radon level of 16.0 pCi/L, which substantially exceeds the EPA action level of 4.0 pCi/L and indicates a serious radon concern for zip code 98862. Given these elevated readings, all homeowners should test immediately and consider mitigation systems, especially in the area's log homes and mountain residences with potential basement or crawl space foundations.

16.00

pCi/L average

Above EPA Action Level

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

4.0 EPA

10+

Winthrop, WA Radon Mitigation

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

Winthrop, WA Radon Testing

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

Winthrop, Washington Radon Levels

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

Radon Level	City	Home Age	Foundation	Submitted
16 pCi/L	Winthrop, WA	0-20 Years	Partial Basement	Feb 2024
12 pCi/L	Winthrop, WA	21-50 Years	Partial Basement	Nov 2021
20 pCi/L	Winthrop, WA	0-20 Years	No Basement/All Slab	Feb 2020

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

Winthrop Radon Facts

Key details about the radon risk profile for Winthrop and the 98862 zip code area.

EPA Radon Zone

Zone 1 — High Risk

County

Okanogan County, WA

Zip Code

98862

Predicted Screening Level

> 4.0 pCi/L (Zone 1)

Avg. User Submitted Level

16.00 pCi/L

User Tests Submitted

Winthrop and the 98862 zip code are located in Okanogan 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 Winthrop, WA

What is the average radon level in Winthrop, WA?

Based on 3 user-submitted tests, the average radon level in Winthrop is 16.00 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 Winthrop in?

Winthrop and the 98862 zip code are in Okanogan 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 Winthrop?

Radon mitigation in Winthrop 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 Winthrop?

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 Washington

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

City	Avg User Radon Level	Submissions
Vancouver	6.56 pCi/L	9
Kent	3.60 pCi/L	5
Seattle	5.25 pCi/L	4
Olympia	5.00 pCi/L	4
Bellevue	3.75 pCi/L	4
Spokane	11.67 pCi/L	3
Camas	8.00 pCi/L	3
Centralia	7.00 pCi/L	3
Bellingham	4.50 pCi/L	2
Kirkland	4.50 pCi/L	2
Washougal	8.00 pCi/L	1
Ridgefield	5.00 pCi/L	1
Moses Lake	No submissions	0