Castle Rock, CO Radon Mitigation and Testing

Q: What EPA Radon Zone is Castle Rock in?

Castle Rock is in Douglas County, EPA Zone 1.

Q: How much does radon mitigation cost in Castle Rock?

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

Douglas County

EPA Zone 1

This Denver Metro community in Douglas County sits along Colorado's Front Range where granite and sedimentary bedrock create EPA Zone 1 conditions with high radon potential. Castle Rock's rapid suburban growth has produced numerous subdivisions with full basements, foundation types that readily facilitate radon accumulation. Testing data for zip codes 80104, 80108, and 80109 is currently limited, making individual home testing crucial for all residents.

Castle Rock, CO Radon Mitigation

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

Castle Rock, CO Radon Testing

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

Castle Rock Radon Facts

Key details about the radon risk profile for Castle Rock and the 80104 zip code area.

EPA Radon Zone

Zone 1 — High Risk

County

Douglas County, CO

Zip Code

80104

Predicted Screening Level

> 4.0 pCi/L (Zone 1)

Castle Rock and the 80104 zip code are located in Douglas County, which has an EPA assigned Radon Zone of 1. A radon zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L. The EPA recommends testing every home regardless of zone classification.

Radon FAQ for Castle Rock, CO

What EPA Radon Zone is Castle Rock in?

Castle Rock and the 80104 zip code are in Douglas 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.

How much does radon mitigation cost in Castle Rock?

Radon mitigation in Castle Rock 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 Castle Rock?

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 Colorado

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

City	Avg User Radon Level	Submissions
Fairplay	12.00 pCi/L	9
Crested Butte	8.56 pCi/L	9
Denver	6.22 pCi/L	9
Montrose	9.25 pCi/L	8
Gunnison	7.38 pCi/L	8
Buena Vista	12.57 pCi/L	7
Pueblo	10.67 pCi/L	6
Grand Junction	8.17 pCi/L	6
Bayfield	6.00 pCi/L	6
Canon City	10.80 pCi/L	5
Aurora	7.40 pCi/L	5
Windsor	7.00 pCi/L	5
Telluride	6.80 pCi/L	5
Parker	5.40 pCi/L	5
Salida	15.50 pCi/L	4
Johnstown	9.50 pCi/L	4
Granby	9.00 pCi/L	4
Longmont	8.00 pCi/L	4
Edwards	6.75 pCi/L	4
Mancos	6.00 pCi/L	4