California, MO Radon Levels

Q: What EPA Radon Zone is California in?

California is in Moniteau 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.

Check local California radon levels and find certified testing and mitigation professionals to keep your home safe

California, MO Radon Facts

EPA Radon Zone Zone 2 — Moderate Risk 2–4 pCi/L (Zone 2)

County Moniteau County, MO

Zip Code 65018

Found in Moniteau County in central Missouri near both Columbia and Jefferson City, California sits over limestone and dolomite bedrock characteristic of the Missouri River valley region. While testing data for zip code 65018 is currently limited, the geological conditions suggest potential for moderate radon levels that warrant individual home testing. The community's location between two metro areas provides access to radon services while maintaining its rural residential character.

4.62

pCi/L area average

Above EPA Action Level

Nearby homeowner readings average 4.62 pCi/L, based on 13 tests from 10 nearby cities. No readings have been submitted for California yet, so the closest recorded data is shown as a benchmark. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

California, MO Radon Mitigation

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

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Radon Readings Near California, MO

No homeowner tests have been submitted for California yet. The closest cities with user-submitted radon data are shown below — explore them to gauge local conditions. Radon varies by home, so testing is the only way to know your level.

City	Distance	Avg User Level	Readings
Jefferson City	19.2 mi	6.00 pCi/L	1
Holts Summit	23.2 mi	4.00 pCi/L	1
Boonville	25.3 mi	4.00 pCi/L	1
Columbia	26.6 mi	3.00 pCi/L	2
Gravois Mills	29.3 mi	7.00 pCi/L	1
Sunrise Beach	34.8 mi	5.00 pCi/L	2
Cole Camp	36.8 mi	5.00 pCi/L	1
Sedalia	37.4 mi	6.00 pCi/L	1

Moniteau County Radon Profile

The soils and bedrock of Moniteau County place it in EPA Radon Zone 2, a moderate-risk classification with predicted indoor averages of 2 to 4 pCi/L. Few homeowner tests have been logged inside Moniteau County so far, which is why this page draws on the nearest recorded readings to illustrate regional radon levels. Since radon is the second leading cause of lung cancer nationally, the EPA urges every household in Moniteau County to test, as levels can differ between neighboring homes.

Radon FAQ for California, MO

What EPA Radon Zone is California in?

California and the 65018 zip code are in Moniteau 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.

Why are radon readings shown from areas near California?

No homeowner radon tests have been submitted for California yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the Moniteau County average—are the best available indicator of local conditions until California homeowners submit their own results. The EPA still recommends testing every individual home, since levels can vary significantly from house to house.

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.