Amherst, SD Radon Mitigation and Testing

Q: What EPA Radon Zone is Amherst in?

Amherst is in Marshall County, EPA Zone 1.

Q: How much does radon mitigation cost in Amherst?

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

Marshall County

EPA Zone 1

Positioned in rural Marshall County on South Dakota's northeastern prairie, Amherst lies within EPA Zone 1 where radon testing data for zip code 57421 remains limited. The area's glacial till soils over underlying sedimentary formations can still produce concerning radon levels in individual homes. Testing remains essential for homeowners, particularly those with basements or ground-contact foundations common in this agricultural region.

Amherst, SD Radon Mitigation

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

Amherst, SD Radon Testing

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

Amherst Radon Facts

Key details about the radon risk profile for Amherst and the 57421 zip code area.

EPA Radon Zone

Zone 1 — High Risk

County

Marshall County, SD

Zip Code

57421

Predicted Screening Level

> 4.0 pCi/L (Zone 1)

Amherst and the 57421 zip code are located in Marshall 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 Amherst, SD

What EPA Radon Zone is Amherst in?

Amherst and the 57421 zip code are in Marshall 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 Amherst?

Radon mitigation in Amherst 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 Amherst?

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 South Dakota

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

City	Avg User Radon Level	Submissions
Spearfish	7.75 pCi/L	4
Rapid City	10.50 pCi/L	2
Aberdeen	8.50 pCi/L	2
Sioux Falls	6.00 pCi/L	2
Watertown	6.00 pCi/L	2