Sequim, WA Radon Mitigation and Testing

Q: What EPA Radon Zone is Sequim in?

Sequim is in Clallam County, EPA Zone 3.

Q: How much does radon mitigation cost in Sequim?

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

Clallam County

EPA Zone 3

Sequim in Clallam County sits on the Olympic Peninsula's rain shadow plain, where marine terrace deposits and glacial till over sedimentary bedrock create generally lower radon potential. The community's housing reflects Pacific Northwest coastal patterns, with many homes built on crawl spaces or slab foundations and relatively few full basements. Testing data remains limited in zip code 98382, though the area's marine-influenced geology suggests reduced radon risk, residents should still consider testing to understand their individual property conditions.

Sequim, WA Radon Mitigation

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

Sequim, WA Radon Testing

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

Sequim Radon Facts

Key details about the radon risk profile for Sequim and the 98382 zip code area.

EPA Radon Zone

Zone 3 — Low Risk

County

Clallam County, WA

Zip Code

98382

Predicted Screening Level

< 2.0 pCi/L (Zone 3)

Sequim and the 98382 zip code are located in Clallam County, which has an EPA assigned Radon Zone of 3. A radon zone of 3 predicts an average indoor radon screening level less than 2 pCi/L. The EPA recommends testing every home regardless of zone classification.

Radon FAQ for Sequim, WA

What EPA Radon Zone is Sequim in?

Sequim and the 98382 zip code are in Clallam County, which has an EPA assigned Radon Zone of 3. A zone of 3 predicts an average indoor radon screening level less than 2 pCi/L.

How much does radon mitigation cost in Sequim?

Radon mitigation in Sequim 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 Sequim?

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