Jefferson, CO Radon Levels

Q: What EPA Radon Zone is Jefferson in?

Jefferson is in Park County, EPA Zone 1.

Q: How much does radon mitigation cost in Jefferson?

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

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

Jefferson, CO Radon Facts

EPA Radon Zone Zone 1 — High Risk > 4.0 pCi/L (Zone 1)

County Park County, CO

Zip Code 80456

Nestled in Park County within the Denver Metro area, Jefferson sits at high elevation where granite bedrock and mountain geology can produce elevated radon levels. Limited testing data for zip code 80456 makes individual home testing especially important for mountain residents. The area's housing includes both seasonal cabins and year-round homes, many with walk-out basements built into hillsides.

12.58

pCi/L area average

Above EPA Action Level

Park County average: 12.58 pCi/L, based on 12 user-submitted tests across 2 cities in the county. No homeowner readings have been submitted for Jefferson itself yet, so this county figure is the closest available benchmark. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Jefferson, CO 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 Jefferson, CO

No homeowner tests have been submitted for Jefferson 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
Bailey	16.6 mi	14.33 pCi/L	3
Fairplay	17.1 mi	12.00 pCi/L	9
Breckenridge	22.6 mi	8.00 pCi/L	1
Conifer	25.9 mi	9.00 pCi/L	3
Dillon	26.9 mi	8.50 pCi/L	2
Evergreen	31.1 mi	10.00 pCi/L	1
Idaho Springs	32.4 mi	4.00 pCi/L	1
Golden	32.6 mi	9.00 pCi/L	2

Park County Radon Profile

The bedrock and soils beneath Park County are classified by the EPA as Radon Zone 1, the highest-risk tier, with predicted average indoor screening levels above 4 pCi/L. Homeowner-submitted tests from 2 cities in Park County average 12.58 pCi/L across 12 tests — above the EPA's 4 pCi/L action level, reinforcing the need for testing across the county. Radon is the second leading cause of lung cancer in the United States, and a short-term test is the only way to confirm a specific home's level in Park County.

Radon FAQ for Jefferson, CO

What EPA Radon Zone is Jefferson in?

Jefferson and the 80456 zip code are in Park County, which has an EPA assigned Radon Zone of 1. A zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L.

Why are radon readings shown from areas near Jefferson?

No homeowner radon tests have been submitted for Jefferson yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the Park County average—are the best available indicator of local conditions until Jefferson 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 Jefferson?

Radon mitigation in Jefferson 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 Jefferson?

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.