Walla Walla, WA Radon Mitigation and Testing

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

Based on 1 user-submitted tests, the average radon level is 6.00 pCi/L.

Q: What EPA Radon Zone is Walla Walla in?

Walla Walla is in Walla Walla County, EPA Zone 2.

Q: How much does radon mitigation cost in Walla Walla?

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

Avg: 6.00 pCi/L

Walla Walla County

EPA Zone 2

1 user test

Located in southeastern Washington's Walla Walla County, this community has recorded an average radon level of 6.0 pCi/L based on available data. This reading exceeds the EPA's 4.0 pCi/L action threshold, reflecting the area's basalt bedrock and loess soil conditions that can facilitate radon accumulation. Homeowners in zip code 99362 should prioritize radon testing and mitigation.

6.00

pCi/L average

Above EPA Action Level

Based on 1 user-submitted radon test for homes in Walla Walla, WA. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Walla Walla, WA Radon Mitigation

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

Walla Walla, WA Radon Testing

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

Walla Walla, Washington Radon Levels

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

Radon Level	City	Home Age	Foundation	Submitted
6 pCi/L	Walla Walla, WA	100+ Years	Partial Basement	May 2025

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

Walla Walla Radon Facts

Key details about the radon risk profile for Walla Walla and the 99362 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

Walla Walla County, WA

Zip Code

99362

Predicted Screening Level

2–4 pCi/L (Zone 2)

Avg. User Submitted Level

6.00 pCi/L

User Tests Submitted

Walla Walla and the 99362 zip code are located in Walla Walla County, which has an EPA assigned Radon Zone of 2. A radon zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L. The EPA recommends testing every home regardless of zone classification.

Radon FAQ for Walla Walla, WA

What is the average radon level in Walla Walla, WA?

Based on 1 user-submitted test, the average radon level in Walla Walla is 6.00 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 Walla Walla in?

Walla Walla and the 99362 zip code are in Walla Walla County, which has an EPA assigned Radon Zone of 2. A zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L.

How much does radon mitigation cost in Walla Walla?

Radon mitigation in Walla Walla 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 Walla Walla?

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