Radon Mitigation in Great Falls, MT

How Radon Mitigation Works

Radon mitigation is the process of installing a vent system that captures radon gas beneath your foundation and releases it above the roof, before it can build up in the air you breathe. For the vast majority of Great Falls homes — and this is basement country — that means an active sub-slab depressurization (ASD) system: a sealed PVC pipe drawn through the basement slab, an inline fan that runs continuously, and a discharge point above the eave.

The physics are simple and reliable. Radon comes from uranium in soil and rock decaying into radium and then into radon gas, which seeps up through cracks, sump pits, floor drains, and the pores in concrete. A mitigation fan puts the soil under your slab at slightly lower pressure than the house, so the gas follows the pipe out instead of drifting up into your living space. Done correctly, it is one of the most dependable fixes in the building trades — and it keeps working for as long as the fan runs, for a few dollars a month in electricity.

A standard radon mitigation install with Great Falls Radon Mitigation includes:

• Diagnostics. We locate the best suction point and check sub-slab communication so the system is sized right the first time.
• Sealing. Slab cracks, sump lids, and the pipe penetration are sealed so the fan pulls from the soil, not your basement.
• Installation. Piping, a correctly rated fan, and a visible U-tube manometer so you can confirm the system is working at a glance.
• Verification. A post-mitigation radon test confirms the level dropped below 4.0 pCi/L. If it hasn't, we adjust until it has.

Six in Ten Cascade County Radon Samples Test High. That's the County's Own Number.

The Cascade City-County Health Department puts it plainly on its own radon page: 60 percent of radon samples collected in Cascade County come back above the EPA action level of 4.0 pCi/L. Statewide, Montana DEQ reports that about half of the homes tested for radon are at or above that level, and the EPA maps Cascade County — along with nearly all of Montana — in Zone 1, its highest radon-potential designation. There is no low-risk corner of this county.

The reason is under our feet. Great Falls is built on the bed of an ice-age lake — the silt and clay of Glacial Lake Great Falls — over dark Cretaceous marine shales, with glacial till and Missouri River terrace gravels mixed through. Add the local housing stock (roughly two-thirds of Cascade County homes were built before 1980, most of them in the basement-heavy boom years around Malmstrom and the smelter) and a heating season that keeps houses sealed roughly half the year, and you get radon numbers that surprise people who just moved here. Read why Great Falls tests so high →

The takeaway for a homeowner is straightforward: county percentages can't tell you what's happening in your house. Two identical homes on the same street can test wildly differently. The only way to know is to test — and if the number is high, to fix it.

Why Homeowners Call Great Falls Radon Mitigation

• Built to the national standard. Montana has no radon-specific license — the state DEQ says outright that it does not certify radon contractors. Anyone with a drill and a fan can sell a system. We build to the ANSI/AARST standards the industry's certifying bodies require, and we'll tell you exactly what that means for your house. Whoever you hire, insist on that.
• We prove the fix. Every radon mitigation job ends with a verification test. You get documentation showing your level before and after — which also matters when you sell, because Montana law requires sellers to hand over known radon test results.
• Firm pricing, no pressure. You get a written price before any work starts, and an honest answer about whether you even need us. If a discounted state test kit is the right next step, we'll say so.
• Built for real-estate deadlines. Under contract with a high radon result? We schedule fast and coordinate with your agent so the deal stays on track.
• Local. We work Great Falls and Black Eagle every day, and cover the surrounding towns — Vaughn, Ulm, Cascade, Belt, and out to Fort Benton.