Radon in Air Remediation in Connecticut & Westchester County NY

Active soil depressurization (ASD) otherwise known as sub-slab depressurization (SSD) is recognized as the Best Available Technology (BAT)for mitigating airborne radon.

ASD is a process whereby a PVC pipe is inserted through the slab level of a structure and is routed to the roofline. An in-line fan is connected to the pipe to draw the radon bearing soil gas through the pipe, exhausting it outdoors.

The ASD process is so successful because we are intercepting the radon before it ever has a chance to permeate up through the slab.

What is Radon?

Radon is a colorless, odorless, tasteless gas created by the natural decay of uranium and radium. It can be found on the Periodic Table of Elements, and its atomic number is 86. Both uranium and radium are naturally occurring, and can be found in all rock and soil to varying degrees. Uranium is the "grandfather" of the radioactive decay chain to which radon is a part of.  The decay chain sequence of uranium is as follows: Uranium 238> Radium 226> Radon 222> lead 214>  bismuth 214> Polonium 214> Lead 210> Bismuth 210> Polonium 210> Lead >206 (stable). Radon is an inert gas, which means it's chemically inactive. Since it is chemically inactive, radon can move easily through all gas-permeable materials. Basements with no visible signs of cracks or penetrations still have radon problems. This is because the gas can permeate directly through concrete.

The most common way radon concentrations are expressed is in "picoCuries per liter" (pCi/L). A pCi/L is one-trillionth of a curie. A "curie" (named after famed Madame Curie) is the amount of activity given off by the decay of one gram of radium, which is the equivalent of 2.2 disintegrations per minute in a liter volume.  Radon is classified as a "Class A" carcinogen which means; positive links have been made between radon exposure and lung cancer from physical models, animal studies and most importantly, human epidemiological studies. The U.S. Surgeon General has stated that radon exposure is the second leading cause of lung cancer in the U.S.

The 4.0 pCi/L action level for radon in the air was established by the EPA because it is technologically feasible to achieve. However, the EPA's position is that there is no "safe threshold" for exposure to ionizing radiation; therefore, the lower your exposure, the better.  The World Health Organization established a 2.7 pCi/l Action Level after years of collective research.  It should be noted that active soil depressurization systems (ASD) installed by Connecticut Basement Systems Radon Inc, often yield post-installation airborne radon results below 2.0 pCi/L.

Dynamics of Airborne Radon Entry

Generally speaking, airborne and waterborne radon concentrations are in a constant state of fluctuation. The biggest reason behind airborne radon fluctuation is due to ever-changing weather patterns. Varying weather conditions create varying pressure differentials, which create varying degrees of influx of soil gas into the structure. The foremost condition recognized to create the greatest influx of airborne radon into a structure is known as the “stack effect”.

This scenario typically occurs in the heating season when the house is generally closed up the majority of the time. As indoor air is heated to a comfortable temperature, it begins to rise or move vertically through the structure. As the heated air moves vertically through the interior envelope of the structure, the structure itself creates a vacuum on the ground. The greater the vacuum, the greater the influx of radon bearing soil gas. It is not uncommon for airborne radon concentrations to fluctuate 100% or more from the cooling season to heating season.


Connecticut Basement Systems Radon Inc began offering airborne radon mitigation services in the summer of 1987, making us the first Connecticut based company to offer this service. We have successfully mitigated airborne radon concentrations as high as 900 pCi/L. Our mitigation experience extends beyond the residential market to include commercial buildings, town halls, daycare facilities, high schools, and complete condominium and detached housing complexes. CBSR has also partnered with environmental firms in utilizing ASD technology for VOC remediation in commercial & residential buildings.

Is the air in your home safe? It all starts with testing. Call us at 1-800-319-8867 to schedule a radon test. Already know you have elevated radon concentrations?  Contact us for effective state-of-the-art airborne and waterborne radon mitigation services. Based in Stratford, we serve clients throughout Connecticut as well as Westchester County New York.