Ariel, WA Radon Mitigation and Testing

Q: What EPA Radon Zone is Ariel in?

Ariel is in Cowlitz County, EPA Zone 3.

Q: How much does radon mitigation cost in Ariel?

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

Cowlitz County

EPA Zone 3

Positioned in southwestern Washington's Cowlitz County along the Columbia River corridor, Ariel sits on volcanic soils and sedimentary formations that typically produce lower radon levels. Testing data for ZIP code 98603 remains sparse, though Washington's generally moderate radon potential suggests routine testing is advisable. Homes built into hillsides or with basements may warrant particular attention for radon accumulation.

Ariel, WA Radon Mitigation

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

Ariel, WA Radon Testing

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

Ariel Radon Facts

Key details about the radon risk profile for Ariel and the 98603 zip code area.

EPA Radon Zone

Zone 3 — Low Risk

County

Cowlitz County, WA

Zip Code

98603

Predicted Screening Level

< 2.0 pCi/L (Zone 3)

Ariel and the 98603 zip code are located in Cowlitz 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 Ariel, WA

What EPA Radon Zone is Ariel in?

Ariel and the 98603 zip code are in Cowlitz 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 Ariel?

Radon mitigation in Ariel 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 Ariel?

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