Cosmopolis, WA Radon Mitigation and Testing

Q: What EPA Radon Zone is Cosmopolis in?

Cosmopolis is in Grays Harbor County, EPA Zone 3.

Q: How much does radon mitigation cost in Cosmopolis?

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

Grays Harbor County

EPA Zone 3

Situated in Grays Harbor County along Washington's Pacific coast, Cosmopolis sits on marine sediments and alluvial deposits that typically produce lower radon levels. Testing data for the 98537 zip code area remains limited, though the coastal location generally suggests reduced radon risk. Homeowners should still consider testing, as individual properties can vary based on specific soil conditions and construction factors.

Cosmopolis, WA Radon Mitigation

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

Cosmopolis, WA Radon Testing

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

Cosmopolis Radon Facts

Key details about the radon risk profile for Cosmopolis and the 98537 zip code area.

EPA Radon Zone

Zone 3 — Low Risk

County

Grays Harbor County, WA

Zip Code

98537

Predicted Screening Level

< 2.0 pCi/L (Zone 3)

Cosmopolis and the 98537 zip code are located in Grays Harbor 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 Cosmopolis, WA

What EPA Radon Zone is Cosmopolis in?

Cosmopolis and the 98537 zip code are in Grays Harbor 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 Cosmopolis?

Radon mitigation in Cosmopolis 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 Cosmopolis?

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