California, PA Radon Mitigation and Testing

Q: What EPA Radon Zone is California in?

California is in Washington County, EPA Zone 2.

Q: How much does radon mitigation cost in California?

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

Washington County

EPA Zone 2

Located in Washington County southwest of Pittsburgh, California sits within the Appalachian Plateau where Pennsylvanian shale and sandstone formations can contribute to radon accumulation in area homes. Testing data for zip code 15419 remains sparse, making individual assessment crucial for homeowners within the Pittsburgh metropolitan region. The area's mix of older housing stock and newer suburban development creates varied foundation conditions that influence radon entry rates.

California, PA Radon Mitigation

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

California, PA Radon Testing

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

California Radon Facts

Key details about the radon risk profile for California and the 15419 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

Washington County, PA

Zip Code

15419

Predicted Screening Level

2–4 pCi/L (Zone 2)

California and the 15419 zip code are located in Washington 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 California, PA

What EPA Radon Zone is California in?

California and the 15419 zip code are in Washington 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 California?

Radon mitigation in California 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 California?

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 Pennsylvania

Cities with the most user-submitted radon test data in the state.

City	Avg User Radon Level	Submissions
State College	10.00 pCi/L	14
Chambersburg	10.14 pCi/L	7
Easton	12.33 pCi/L	6
Butler	12.40 pCi/L	5
Dingmans Ferry	5.80 pCi/L	5
Hanover	14.00 pCi/L	4
Mechanicsburg	13.75 pCi/L	4
Greenville	10.75 pCi/L	4
Pittsburgh	9.25 pCi/L	4
Albrightsville	9.00 pCi/L	4
Philadelphia	8.00 pCi/L	4
Lackawaxen	15.33 pCi/L	3
York	11.67 pCi/L	3
Elizabethtown	9.67 pCi/L	3
Johnstown	7.33 pCi/L	3
West Chester	6.67 pCi/L	3
Danville	5.67 pCi/L	3
Springfield	5.67 pCi/L	3
East Stroudsburg	5.00 pCi/L	3
Langhorne	4.67 pCi/L	3