Radon in Aspen: What the Numbers Actually Say
Radon is a naturally occurring radioactive gas — colorless, odorless, and tasteless — produced as uranium in rock and soil breaks down. The EPA classifies it as a Class A carcinogen: it's the second-leading cause of lung cancer in the United States and the number-one cause among people who have never smoked, linked to roughly 21,000 deaths a year.
Colorado sits near the top of the national risk map. The state health department's own headline is blunt: about half of Colorado homes have elevated radon. Locally it's the same story. Pitkin County is in EPA Zone 1 — the highest-risk designation — and county environmental health staff report that roughly 40–50% of homes tested in the Aspen area come back above the EPA action level of 4.0 pCi/L. Garfield County, down-valley, is also Zone 1 with about 40% of tests high. Eagle County is mapped Zone 2, but real-world testing shows roughly 40–45% of its homes exceed the action level anyway — the map is a prediction; your test is the truth.
None of this is new to Aspen. The city was the first municipality in Colorado to put radon requirements into its building code, back in 2003, and Pitkin County publishes maps of local test results and hands out free test kits every January. The local risk is documented, public, and taken seriously by the people who write our building codes. The only unknown is your house.
How Radon Mitigation Works
A mitigation system doesn't filter radon — it stops it from getting inside. The standard approach, sub-slab depressurization, creates gentle suction under your foundation so soil gas is collected below the house and vented above the roof, where it disperses harmlessly.
A proper install in a valley home looks like this:
- Diagnostics first. We check how air actually moves under your slab — called a communication test. In rocky mountain soils this step is the difference between a system that works and one that just hums.
- Suction point and sealed piping. A suction cavity below the slab (or the sump pit, when the home has drain tile), connected to sealed PVC routed through the interior and attic where possible — which keeps pipe off your siding — or painted to match on a rear elevation.
- The fan, outside living space. Code puts the inline fan in the attic, garage, or outdoors — never in the basement — so any leak on the pressure side stays out of your air.
- A manometer you can read. The small U-shaped gauge on the pipe shows system vacuum at a glance. If the fluid ever levels out, the fan has stopped — call us.
- Verification testing. Every install ends with a 48-hour post-mitigation test. You get a number, not a promise. Mitigated homes typically land under 2 pCi/L, often under 1.
Done right, the system is about as loud as a refrigerator and costs roughly $60–$120 a year in electricity to run continuously. Where a run passes near bedrooms, we use quieter EC fans and vibration couplings — in a home you paid Aspen prices for, the system should be something you forget exists.
Why Mountain Homes Are Different
Front Range tract homes mostly sit on one simple slab. Roaring Fork Valley homes don't. Hillside lots produce walkout basements with uneven pressure below grade; decades of additions leave one house with a basement and a crawlspace and slab-on-grade sections; and modern Aspen construction is sealed tight for energy efficiency, which — counterintuitively — often traps more radon than an old drafty house ever held. High-altitude winters make it worse: a 7-month heating season drives the stack effect that pulls soil gas indoors, exactly when every window is shut.
That's why quotes here can run above the numbers you'll read on national cost sites, and why we design multi-point systems for mixed foundations rather than forcing a one-slab solution onto a three-foundation home. If your lower level is finished — most in Aspen are — routing and aesthetics get engineered in from the start, not patched after.
Test First. It Might Cost You Nothing.
Here's something a radon company probably shouldn't lead with: you may not need to pay anyone to find out where you stand. The City of Aspen hands out free test kits year-round at City Hall, Pitkin County offers them every January, and Garfield and Eagle counties run their own programs. If a kit comes back low, wonderful — retest in a couple of years, and sooner if you renovate.
Where we come in: results near or above 4.0 pCi/L, conflicting numbers, real-estate deadlines that need a licensed measurement professional's continuous-monitor test, or a home that needs a fix. We'd rather earn the mitigation job honestly than scare anyone into a test they could have gotten free.
Licensed — and You Can Check
Since July 1, 2022, Colorado law (HB21-1195) requires anyone offering radon measurement or mitigation services to hold a state license through DORA, built on national NRPP certification. That was a good day for homeowners: it ended the era of anyone-with-a-drill radon work. Verify any radon contractor — including us — through DORA's public Check a License lookup before you hire. If a bid lands in your inbox from someone who isn't licensed, that's your answer.
From Aspen to Glenwood Springs
We serve the full CO-82 corridor and the Crystal River Valley: Aspen — the West End, Red Mountain, Smuggler, Starwood, East Aspen, and McLain Flats — plus Snowmass Village, Old Snowmass, Woody Creek, Basalt, El Jebel, Carbondale, Redstone, and Glenwood Springs. Homes on wells in McLain Flats and Old Snowmass: ask about radon in well water — it's a real thing here.
