Grand Coulee, WA Radon Mitigation and Testing

Q: What EPA Radon Zone is Grand Coulee in?

Grand Coulee is in Grant County, EPA Zone 2.

Q: How much does radon mitigation cost in Grand Coulee?

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

Grant County

EPA Zone 2

Located in Grant County along the Columbia River plateau, Grand Coulee sits within zip code 99133 in an area characterized by basalt bedrock and sandy soils. While radon testing data for this community remains limited, the underlying geology can still produce variable radon levels in individual homes. Homeowners should consider testing to establish baseline radon levels for their specific property.

Grand Coulee, WA Radon Mitigation

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

Grand Coulee, WA Radon Testing

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

Grand Coulee Radon Facts

Key details about the radon risk profile for Grand Coulee and the 99133 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

Grant County, WA

Zip Code

99133

Predicted Screening Level

2–4 pCi/L (Zone 2)

Grand Coulee and the 99133 zip code are located in Grant 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 Grand Coulee, WA

What EPA Radon Zone is Grand Coulee in?

Grand Coulee and the 99133 zip code are in Grant 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 Grand Coulee?

Radon mitigation in Grand Coulee 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 Grand Coulee?

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