A month ago I wrote about the installation of a radon mitigation system in my home. Before the install, the level in the basement measured 12.1 pCi/L , while the level on the first floor measured 6.0 pCi/L.
After the installation of the active mitigation system, the level on the first floor of the house was reduced to 2.6 pCi/L, as measured with a charcoal detector made by Air Chek. I haven’t rechecked the basement yet.
In addition to the lower radon reading, I’ve noticed that the basement humidity averages about 65%, and doesn’t rise much even after a good rain. That might make for the most useful result: no more soggy cardboard storage boxes.
About eight weeks ago I decided to test my home for radon, as I had bought the house “as-is” two years ago and never got around to testing for it.
I used RSSI’s Alpha-track Radon Detector and placed one in the living room on the first floor for six weeks. The reading came back at 6 pCi/L, which is a bit above the EPA recommended action level of 4 pCi/L. To put the pCi/L value into mrem terms, living for a year in an environment with a radon concentration of 4 pCi/L is roughly equivalent to a whole-body dose of 800 mrem. Much more information on radon and the average levels in your area of Illinois can be found by visiting the IEMA radon website.
I decided to install a sub-slab depressurization (SSD) system in the basement of my home. The system cost is around a thousand dollars for parts and labor, and my installation took one worker about four hours to complete. There are a variety of state-licensed companies and individuals that will do the installation, but I went through VSI. I thought they did a good job. You’ll find a lot of detailed information about the general specifications of an SSD system on their website. Below are some pictures of the installation and the sealed sump cover.
After only a few hours of the system running, I noticed that the typical musty smell of the basement had left, and the humidity had dropped to about 50%. The fan and the negative pressure field it creates below the slab of the concrete basement, draws out not only the radon, but also water vapor and other soil gases that would have normally just entered the house. I’m going to recheck the radon levels with a short-term test unit from Air Chek to confirm the effectiveness of the SSD system.