EPA Zone 1 · Minnehaha & Lincoln County

Radon Testing & Mitigation
in Sioux Falls, SD

Minnehaha and Lincoln Counties are designated EPA Zone 1 — the highest-risk category in the country. Whether you're in Falls Park, Harrisburg, Tea, or Brandon, find out your home's radon level before it becomes a long-term health concern.

  • Minnehaha & Lincoln County Coverage
  • Same-Day Scheduling Available
  • Written Reports Included
  • All 5 Service Types Available
  • Free Estimates

Radon Risk in the Sioux Falls Area

Understanding why the Sioux Falls region carries elevated radon risk.

Sioux Falls sits in the heart of EPA Zone 1 — a designation given to areas with a predicted average indoor radon level above 4.0 pCi/L. Both Minnehaha County (home to the city proper) and Lincoln County (where Harrisburg, Tea, and other fast-growing suburbs are located) carry this highest-risk designation.

The primary geological driver is glacial till — sediment deposited by retreating glaciers over uranium-bearing formations including Pierre Shale. Pierre Shale naturally contains elevated uranium concentrations, which decay into radium and then into radon gas. Glacial till is highly permeable, meaning soil gases move readily through it and can enter homes through foundation cracks, floor-wall joints, and other penetrations.

The Big Sioux River valley and surrounding terrain create micro-variation in radon levels between neighborhoods — which is why two homes on the same block can have different results. Individual testing is the only way to know your home's actual level.

Homes in Brandon, Dell Rapids, Crooks, and rural Minnehaha County properties face similar risk. New construction in Lincoln County — driven by Sioux Falls's expansion into Harrisburg and Tea — is not inherently safer: passive radon-resistant construction reduces risk but does not eliminate it.

Zone 1

EPA Radon Zone — Minnehaha County

Zone 1

EPA Radon Zone — Lincoln County

4.0

pCi/L — EPA recommended action level

SD

Among highest median indoor radon in the US

What Sets Our Sioux Falls Service Apart

Six reasons Sioux Falls area homeowners and real estate professionals choose us for radon testing and mitigation.

Local Area Coverage

We serve the full Sioux Falls metro — Minnehaha and Lincoln County, including Harrisburg, Tea, Brandon, Dell Rapids, and surrounding rural properties.

All Testing Types

Short-term, long-term, real estate transaction, and commercial multi-point testing — all options available for every situation.

Written Reports Included

Every service includes a written report with results, context, and next-step recommendations — not just a number on a slip of paper.

Transparent Pricing

Clear pricing ranges with no hidden fees. We'll discuss what's included before any work begins so there are no surprises on the invoice.

Same-Day Scheduling

Most appointments scheduled within 24–48 hours. Same-day service available when the schedule allows — especially for urgent real estate situations.

Family-Centered Approach

We explain results in plain language, answer questions honestly, and treat your home and family with the same care we'd want for our own.

Areas We Serve in and Around Sioux Falls

Service area map — Minnehaha & Lincoln County, SD

Neighborhoods & Communities Served

  • Downtown Sioux Falls
  • Falls Park Area
  • South Sioux Falls
  • West Sioux Falls
  • Prairie Green
  • Harrisburg
  • Tea
  • Brandon
  • Dell Rapids
  • Crooks
  • Hartford
  • Baltic

ZIP Codes Served

57101 57103 57104 57105 57106 57107 57108 57110 57032 57064 57005 57004

Ready to Test Your Sioux Falls Home?

EPA Zone 1 means the risk is real — and the only way to know your level is to test. Most appointments scheduled within 24–48 hours.

We Also Serve Nearby Cities

Radon services across eastern South Dakota — not just Sioux Falls.

Sioux Falls Radon FAQs

Minnehaha and Lincoln Counties are both designated EPA Zone 1 — the highest-risk category, indicating a predicted average indoor radon level above 4.0 pCi/L. South Dakota consistently ranks among states with the highest measured indoor radon levels, and the Sioux Falls area is squarely in that elevated-risk region. Knowing your home's specific level requires testing.
Yes. The same glacial till and Pierre Shale geology that elevates radon across Minnehaha County extends into Lincoln County. Harrisburg and Tea — among the fastest-growing communities in South Dakota — are built on the same underlying geology. New construction there is not exempt from radon risk, and radon levels vary home by home regardless of neighborhood or age.
South Dakota adopted IRC radon-resistant construction provisions for new homes in Zone 1 counties, including Minnehaha and Lincoln. These passive systems (a gravel layer, vapor barrier, and rough-in pipe) reduce risk but do not guarantee levels below 4.0 pCi/L. A fan activation or full mitigation system may still be needed. Testing after occupancy is the only way to confirm actual radon levels in a new home.
South Dakota does not mandate radon testing for existing home sales, but radon testing is a common buyer contingency in the Sioux Falls real estate market — particularly given the Zone 1 designation. Sellers who can demonstrate a known radon level (especially a low one) often find the transaction moves more smoothly. Real estate agents in the area are generally familiar with the process.
The Sioux Falls area sits on glacial till deposited over uranium-bearing formations, including Pierre Shale. Pierre Shale has naturally elevated uranium concentrations, which decay into radium and then into radon gas. Glacial till is highly permeable, allowing soil gases to migrate into homes through foundation penetrations. The Big Sioux River valley and local terrain create variation in radon levels between neighborhoods — which is why individual home testing matters even within the same block.
Most appointments in the Sioux Falls area are scheduled within 24–48 hours of inquiry. Same-day appointments are available when the schedule allows. After device retrieval, written results are typically delivered within 24 hours. For real estate transactions, we coordinate directly with agents to meet closing timelines — contact us with your closing date and we'll work backward from there.