Why a Radon Reduction System Matters for Metro East Homes
Understanding the Risks in Metro East Illinois
If you live in Belleville IL, Edwardsville IL, or O'Fallon IL, you probably know someone who has tested their home for radon. That is because much of Metro East Illinois sits in an EPA radon zone rated moderate to high. The soil here contains uranium-bearing minerals that break down over time and release radon gas. That gas seeps into homes through cracks in the foundation, gaps around pipes, and even through the concrete slab itself. I have seen houses where the indoor radon level was over four times the EPA action level, and the owners had no idea until they ran a proper radon test.
The good news is that radon is a problem you can fix. The better news is that you do not have to live with a noisy, unsightly machine running forever if you plan ahead. The key is choosing the right radon reduction system for your home. Whether you are building new or retrofitting an existing house, the goal is the same: lower the indoor radon concentration to below 4 pCi/L, and keep it there.
Active versus Passive Systems
There are two main approaches to radon mitigation: active and passive. A passive radon system relies on natural air pressure and convection to pull soil gas away from the house. Builders sometimes install a passive system during radon-resistant new construction by placing a layer of gravel under the slab, running a vent pipe up through the house, and sealing cracks in the foundation. Under the right conditions - a tight house, good stack effect, and low soil moisture - a passive system can keep radon levels low without any moving parts.
But passive systems do not work everywhere. In Metro East, where clay soils and high water tables can reduce the effectiveness of soil suction, an active radon system is usually required. An active system uses a radon fan to create continuous suction under the slab. That active draw pulls radon-laden air from beneath the foundation and exhausts it safely above the roofline. The fan itself is a small appliance, typically mounted in the attic or outside the home. It runs 24/7, but the electricity cost is often less than running a 60-watt light bulb.
Sub-Slab Depressurization: The Workhorse
The most common method for an active system is sub-slab depressurization. A contractor drills a hole through the concrete floor, digs out a small cavity in the soil below, and inserts a suction pipe. That pipe connects to a radon fan, which pulls the gas from under the slab and sends it up a vent stack. The fan creates a low-pressure zone beneath the house, so any radon gas trying to enter gets drawn into the pipe instead.
This technique works well across the varied geology of the Metro East area. I have seen it bring a home in O'Fallon IL from 12 pCi/L down to 1.5 pCi/L in a single day. The key is proper sealing. If you skip sealing cracks in the basement floor or around the sump pump, the fan will just pull conditioned air from inside the house rather than soil gas from below. That wastes energy and reduces the system's effectiveness.
Components of a Good Radon Reduction System
A well-designed radon reduction system includes several parts that work together. Here is what you can expect to find in a typical installation:
- Suction pit and pipe: A 3- or 4-inch PVC pipe extends through the slab into a small gravel bed. This is the pickup point for soil gas.
- Radon fan: Brands like RadonAway and Scurion make inline fans designed to run continuously for years. Choose the right size for your house and the pipe run.
- Vent stack: The pipe runs up the side of the house or through the attic and exits above the roofline. This keeps the exhaust away from windows and air intakes.
- Manometer: A U-tube gauge mounted on the pipe shows whether the fan is running and pulling sufficient suction. If the fluid levels are even, the fan has stopped or the system is blocked.
Every one of these components matters. I have seen systems where someone used a cheap bathroom fan instead of a proper radon fan, and it burned out in six months. The radon fan is the heart of the system, so it pays to use a proven brand.
Testing Before and After
You cannot know if your radon reduction system is working unless you test. A radon test before mitigation establishes the baseline. For the initial measurement, many homeowners use a charcoal canister test. You expose the canister for two to four days, then mail it to a lab. It is simple and inexpensive, but it only gives a snapshot. Radon levels fluctuate with weather and season, so a single short-term test can be misleading.
For the post-mitigation verification, I recommend a continuous radon monitor. These electronic devices record radon levels hourly for several days or weeks. They show you the peaks and valleys, and they help confirm that the system is holding levels low through changes in temperature and barometric pressure. Air Sense Environmental uses continuous monitors for their follow-up testing to ensure the mitigation is solid.
Crawlspace Considerations
Not every home in Belleville IL or Edwardsville IL has a full basement. Many have crawlspaces. Crawlspace ventilation is a different animal. You cannot use sub-slab depressurization if there is no slab. Instead, the strategy is to seal the crawlspace floor with a heavy polyethylene liner, seal the vents, and then connect a radon fan to the liner to pull soil gas from under the plastic. It is more labor-intensive but just as effective.
One thing I always check in crawlspace homes is the condition of the vapor barrier. If it is torn or missing, a radon reduction system will struggle. The fan will pull air through the gaps instead of from the soil. Taking the time to patch and seal the liner makes the system work the way it should.
Retrofit versus New Construction
If you are building a new home in the Metro East area, radon-resistant new construction is the smart move. The cost to install a passive radon system during the build is minimal - just a few hundred dollars for the gravel bed, pipe, and sealing. Even if you do not activate the system right away, you have the infrastructure in place. Later, if a radon test shows high levels, you can add a radon fan and convert it to an active system.
For existing homes, a retrofit radon reduction system is more involved but still very doable. The contractor has to core through the slab, excavate a suction pit, and run the vent pipe to the exterior. The cost varies with the difficulty of the pipe run and the number of suction points needed. Most single-family homes need only one suction point, but larger houses or those with multiple foundation sections may need two.
Long-Term Maintenance
A radon reduction system is not a set-it-and-forget-it installation. The fan should last five to ten years, but it can fail earlier if it gets wet or if the bearings wear out. Check the manometer every month. If the fluid levels change, something is wrong. Also, look for any new cracks in the foundation or slab. Over time, settling can open pathways that bypass the system. Sealing cracks is a simple DIY task that keeps the system efficient.
Every two years, run another radon test. I prefer a continuous radon monitor for the follow-up because it catches intermittent problems. If you see levels creeping up, you can address the issue before it becomes a health concern.
Choosing a Professional
Radon mitigation is not a general handyman job. It requires knowledge of soil gas dynamics, building science, and local geology. A certified contractor like Air Sense Environmental understands the specific conditions in Belleville IL, Edwardsville IL, and O'Fallon IL. They know which fan size works for a typical two-story colonial and how to route the vent stack without violating code. They also carry the right liability insurance and use calibrated test equipment.
When you interview a contractor, ask about their experience with active radon systems. Ask what brand of fan they install and whether they provide a warranty. A reputable company will stand behind their work and offer a guarantee that the post-mitigation test will be below 4 pCi/L.
The Bottom Line
Radon is a serious hazard, but it is also a solvable one. A properly designed and installed radon reduction system can bring your indoor levels down to near-background concentrations. The cost is modest compared to the peace of mind it provides. If you have not tested your home, order a charcoal canister test today. If you already know you have a problem, call a local specialist. Living in a high-EPA radon zone does not mean you have to accept high radon levels. With sub-slab depressurization, a good radon fan, and regular testing, you can protect your family without turning your home into a construction site.