CT Basement Systems Radon Blog by Matthew A. Bednarz V.P.


Posted by Matthew Bednarz on Thu, Jan, 18, 2018 @ 14:01 PM

January is Radon Action Month (RAM).  January was chosen as RAM primarily because indoor radon concentrations are at their "worst case" or highest levels for the year.  Radon entry into buildings is based on pressure differentials.  These pressure differentials are exacerbated during the heating season due to the "stack effect".  The stack effect is a scenario whereby heated air rises within a structure via thermal bypasses, which induces the structure to increase suction on the ground on which it sits.  This in-turn, increases the influx of soil gas into the structure, thereby increasing airborne radon concentrations.


Testing airborne radon concentrations this time of year will generally give a "worst case" scenario for radon.  Point being; if your radon testing indicates levels > 4 pCi/l, the likelihood that your annual average is going to be below 4.0 pCi/l is very good.  On the other hand, if your radon levels are > 4 pCi/l, this gives indication that at the very least; further testing is warranted.  Radon mitigation should never be based on one result.  But the higher above 4.0 pCi/l you are, the more confident you can become that there is a problem. 

There's an old saying that states; "no news is good news"...maybe it would be if something different was discovered about radon exposure that indicated it was less of a problem than originally thought.  The reality; nothings changed.  Radon is still recognized as the leading cause of lung cancer in non-smokers, and the second cause of lung cancer overall.  It's the intangible aspect of radon that make events like RAM necessary...to remind us of the hidden danger.

The other facet of radon that is sometimes overlooked - but is still important to consider  is waterborne radon.  For those of us whose daily water usage is supplied from a private drinking water well, radon has a second "highway" into your home.  When you test your air for radon - you should also test the water.  As is the case with any water contaminant, waterborne radon levels can fluctuate.  A low reading 3, 8, 11 years ago in no way assures a low reading going forward.


Contact us for Radon Testing  in Air & Water





Topics: waterborne radon removal, radon, soil gas


Posted by Matthew Bednarz on Tue, Oct, 09, 2012 @ 16:10 PM

 radon in water

 The two most prominet technologies for waterborne radon mitigation are Granular Activated Carbon (GAC) filtration and Aeration.  Unlike aeration; GAC is a passive technology whereby water pumped from a well flows through tanks packed with granular activated carbon.  As the water runs through the carbon; the radon is removed from the water and deposited onto the GAC by the process of "adsorption".  Adsorption is different from "absorbtion"...adsorption is when matter or a gas (in this case - radon) - adheres to the surface of a solid (GAC).  Absorbtion means to "drink in"...like a sponge dose with water.  Depending on influent water quality; GAC filtration is capable of removal rates as high as 99% (at least initially).

GAC system with water treatment system

Removal efficiencies of a GAC systems do vary according to contaminant load in the influent water.  Organic (ie; tannins) and synthetic organic substances (ie; pestisides) will also adsorb - or collect onto the GAC beds.  While the homeowner may appreciate the improved water quality subsequent to a GAC install - the adsorption of other known or unknown contaminants can become problematic in the service life and performance of the system.

Even though aeration is recognized by the EPA as the best available technology (BAT) for waterborne radon removal; GAC filtration is a viable alternative in certain situations.  First priority in deciding whether or not a GAC install is appropriate is waterborne radon levels.  Excessive influent radon concentrations that are adsorbed on the carbon bed will generate gamma emmisions off the tank walls of the system.  The stronger the radon concentration deposited on the GAC - the farther the extent of the gamma ray emmisions.  This can create exposure issues especially when the system is located in direct proximity to frequently occupied space.

GAC with pre and post filters

Other aspects of a GAC filtration system installation are proposed system location, influent contaminant load or water quality (ie; iron, manganese, etc.), flow rate, and system demand (volume of water to be treated).

Initial install cost of a GAC filtration system are almost always more attractive.  However; long term maintenance cost can oftentimes exceed operating and mainteance expense of an aeration system.  Demand placed on the system and water quality are the biggest influential factors to this variable.

Aqua Boost VFD  with chlorine removal on city water resized 600

An alternate application for GAC is for the filtration of municipally supplied water.  Virtually all pitcher and faucet filters found in grocery stores and home improvement centers have some degree of GAC incorporated into their design.  The major focus of these filters is chlorine removal.  Municipalities impart a chlorine residual for sterilization maintenance of their distribution systems.  This residual is not necessary once the water is in your distribution system...much less - desireable for consumption.  We can provide a chlorine test packet to our city water customers so they can see how much chlorine is in their water.

contact us for a chlorine test packet or a quote for a GAC system

water treatment specialist



Topics: waterborne radon removal, GAC systems, GAC Filtration, adsorption, granular activated carbon