San Gregorio, CA Radon Mitigation and Testing

Q: What EPA Radon Zone is San Gregorio in?

San Gregorio is in San Mateo County, EPA Zone 2.

Q: How much does radon mitigation cost in San Gregorio?

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

San Mateo County

EPA Zone 2

Nestled in the coastal hills of San Mateo County along the San Francisco Peninsula, San Gregorio sits on mixed geological formations including marine terraces and coastal range bedrock that can influence local radon conditions. The area features predominantly rural and semi-rural residential properties, many with older construction and varied foundation types ranging from pier-and-beam to partial basement designs. With limited testing data currently available, homeowners in this scenic coastal community are encouraged to conduct radon testing to establish baseline levels for their specific properties.

San Gregorio, CA Radon Mitigation

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

San Gregorio, CA Radon Testing

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

San Gregorio Radon Facts

Key details about the radon risk profile for San Gregorio and the 94074 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

San Mateo County, CA

Zip Code

94074

Predicted Screening Level

2–4 pCi/L (Zone 2)

San Gregorio and the 94074 zip code are located in San Mateo 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 San Gregorio, CA

What EPA Radon Zone is San Gregorio in?

San Gregorio and the 94074 zip code are in San Mateo 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 San Gregorio?

Radon mitigation in San Gregorio 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 San Gregorio?

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 California

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

City	Avg User Radon Level	Submissions
Los Angeles	7.83 pCi/L	6
Mammoth Lakes	10.80 pCi/L	5
San Jose	4.20 pCi/L	5
Rancho Palos Verdes	8.00 pCi/L	4
Woodland Hills	7.67 pCi/L	3
South Lake Tahoe	6.33 pCi/L	3
Palos Verdes Peninsula	6.00 pCi/L	3
Bishop	5.67 pCi/L	3
Sacramento	4.33 pCi/L	3
Oakland	3.33 pCi/L	3
Fresno	10.00 pCi/L	2
Davis	8.00 pCi/L	2
Palo Alto	6.50 pCi/L	2
Studio City	6.50 pCi/L	2
Menlo Park	5.00 pCi/L	2
Truckee	5.00 pCi/L	2
Walnut Creek	4.00 pCi/L	2
San Diego	3.50 pCi/L	2
San Francisco	3.50 pCi/L	2
Belmont	20.00 pCi/L	1