Radon Mitigation in Summerset, SD

One of South Dakota's Newest Cities, Built on Some of Its Oldest Rock

Summerset only incorporated in 2005, and the subdivisions filling in along I-90 between Black Hawk and Piedmont make it feel newer still. But a city charter is paperwork; the ground is Precambrian. The Black Hills' granite-and-metamorphic core carries naturally uranium-bearing rock, and as that uranium decays to radium and then to radon gas, the gas rises into whatever's built on top — whether the slab cured forty years ago or last fall. The EPA and USGS map a high-radon-potential ridge around the Hills, and Summerset's corridor is on it.

So the question for a Summerset homeowner isn't "is my house too new for radon?" — it's "what does my house actually read?" Roughly half of tested South Dakota homes come back above the EPA action level of 4.0 pCi/L, and the only way to find out which half yours is in is a 48-hour test. More on the geology here →

Why "New Build" Doesn't Mean "Radon-Safe"

Radon doesn't check the certificate of occupancy. It enters through the same paths in a new slab as an old one — shrinkage cracks, control joints, utility penetrations, sump pits — and a newly built home over active soil gas can test just as high as its older neighbors. Two houses on the same Summerset street, framed the same summer by the same crew, can still return very different numbers.

A few things about testing a newer Summerset home:

• Test after you move in, not just at closing — a house that's lived-in and closed up reads differently than an empty one with doors swinging all day.
• Winter tells the truth. South Dakota's long closed-house season is when radon concentrates, and when a test best reflects real conditions.
• Free is fine. The DANR's 500 free annual test kits are a legitimate first step; save the professional test for deadlines and verification.

Passive to Active: Summerset's Head Start

Here's the good news hiding in all that new construction: many newer homes come with a passive radon rough-in already in the walls — a PVC pipe from under the slab through the roof, no fan attached. If your test comes back at 4.0 pCi/L or higher, that pipe means most of the system is already built.

Converting it to a working active sub-slab depressurization system is a short job: we add a correctly rated inline fan, seal the slab details the builder's rough-in didn't, mount a U-tube manometer so you can confirm suction at a glance, and finish with a post-mitigation verification test. The fan then runs quietly around the clock for about $3 a month. Because the piping and roof penetration already exist, conversions typically cost less than the standard from-scratch install, which runs about $1,200–$2,500 in this area — the cost page has the full picture. No pipe in your house? No problem — the from-scratch version installs in a single three-to-five-hour visit, and if you're mid-purchase, our real estate page explains how it fits a closing timeline.