Radon Testing and Mitigation in Greeley, CO
Weld County’s seat and the home of the University of Northern Colorado, Greeley grew from the 1870 Union Colony into a city of 108,795 residents (2020 census), and every one of its neighborhoods sits on ground the EPA flags for radon. Weld County falls inside EPA Radon Zone 1, the highest of the three zones, which means the predicted average indoor screening level across the county runs above 4.0 pCi/L. That is a county-wide potential, not a reading for your specific house, and the only way to know your home is to test it.
What Zone 1 means for Greeley homes
Radon is a soil gas that seeps up through foundation cracks, sump pits, and slab penetrations. Because it comes from the ground, no part of Greeley is automatically safe or automatically at risk. Statewide, CDPHE reports that about half of Colorado homes exceed 4.0 pCi/L, the level at which the EPA advises action. That figure describes Colorado as a whole, not Greeley by itself, but it is a useful reminder that elevated readings are common across the Front Range.
The EPA action level is 4.0 pCi/L. The EPA recommends fixing a home at or above that number and suggests you weigh action between 2.0 and 4.0. A short-term or long-term test placed by a licensed measurement professional gives you the number you need before deciding anything.
Why it matters: radon is the second leading cause of lung cancer in the United States after smoking, and the leading cause among people who have never smoked, according to CDPHE. That health link is the reason the state built a licensing program and a disclosure law around radon rather than leaving it to chance. Testing is inexpensive and quick, and it turns a county-wide statistic into a specific answer about your own Greeley home.
Greeley’s east and west housing split
Greeley has a clear housing-age divide, and it shapes how radon shows up. The older east side and downtown, including Glenmere, Cranford, and Sunrise, hold early-1900s bungalows and Victorians on aging foundations where settling and cracks give radon easy paths indoors. West Greeley tells a different story: the 1990s and 2000s subdivisions of Kelly Farm, Country Club West, and West Point were built on newer slabs, some with modern foundation detailing.
Neither pattern is a guarantee. A century-old bungalow can test low and a 2005 subdivision home can test high, because the driver is the soil under the slab, not the year on the deed. If your Greeley home is a newer build, ask whether it has a passive radon rough-in already in the foundation. Where one exists, activating it with a fan is often a smaller job than a full retrofit. A licensed professional can tell you what you are working with.
Testing and mitigation are licensed work in Colorado
Colorado licenses radon measurement professionals and radon mitigation professionals through the state DORA Division of Professions and Occupations. NoCo Radon Pros is a free matching service and does not hold either license. What we do is connect you with an independent, Colorado-licensed radon professional who tests your home and, if the result warrants it, designs and installs a mitigation system. You can verify any contractor’s credential yourself on the Colorado DORA license lookup before agreeing to work.
If a test comes back at or above 4.0 pCi/L, a standard sub-slab depressurization system is the usual fix. It pulls the radon from beneath the foundation and vents it above the roofline before it can enter living space. For most homes that runs about $1,000 to $2,500, with roughly $1,500 common, though crawl spaces and larger footprints can cost more. Our radon mitigation cost guide breaks down what drives the price, and if your home has an unfinished lower level, our crawl space and basement radon page explains how those spaces change the approach.
Greeley’s mix of older east-side homes with basements and stone or block foundations and newer west-side homes on modern slabs means there is no single template. The professional you are matched with sizes the system to your foundation, your test result, and your home’s layout rather than a one-size number.
Getting matched in Greeley
Whether you are a longtime resident near the UNC campus, a landlord with a Weld County rental, or a homeowner about to list, testing is the first step. If you are selling or buying, Colorado’s disclosure law shapes what has to be shared, and our Colorado radon disclosure law guide covers it. When you are ready, tell us about your home and we will connect you with a licensed local professional. You can also see every Northern Colorado city we cover or learn how our free service is paid.