Radon in Water

Vermont Dept of Health issued an advisory statement regarding dangerous levels of Radon Contamination found in well water throughout the State. They found that it was up 10 times higher than the health advisory level. In one case it was 229 time higher.

Radon in well water is found throughout Vermont. Contamination poses health risks to everyone. The only way to know for sure is to test.

“If you drink water from a well, you need to have it tested regularly”

There are two general approaches to reducing Radon in water, Charcoal Filtration and Aeration. For more than 30 years the choice has been between these approaches. Now you have a second aeration approach to look at. Each has a strength and weakness. Understanding this will enable you to make the best decision for you.

The Ways We Eliminate Radon in Water

Activated Charcoal Method

Water is run through a media of activated charcoal within a canister, trapping the radioactive elements. Simple enough but lets review…the radioactive elements are trapped in a canister in your house. So, not so bad we can stack cinderblocks around the canister they say. I’m not the only one that thinks this is a bad idea. The largest manufacturer of water filtration equipment won’t let its products be used for this purpose. Liability, glowing cats and of course disposal. Where do we take a radioactive canister to get rid of it? Anyway, we don’t do this type of mitigation.

Pro: Cheap
Con: Accumulating radioactive isotopes in your basement…, Limited to only very low Radon concentrations, Frequent filter replacement.

Bubble-Up Method

For the last 30 years, the only game in town. An appliance the size of a clothes dryer us located in the house where the water comes into the house. Typically in the mechanical room. After well water has run through any other treatment and filtration that may be required it enters the enclosed environment of the system and it is sprayed into a collection reservoir. As this happens, radon comes out of solution in the water and becomes a gas. The radon gas is then vented out of the house via 2″ PVC pipe to a point above the roofline. The water is then ready for distribution to the home.

Pro: Very effective, up to 99% reductions in radon levels. If you have radon in water levels over 100,000 pCi/L this is your play.
Con: Expensive to install, power and maintain. The units have a motorized fan and water pressure pump that maintains water at 72 +/- PSI. The units require, at a minimum one service maintenance and cleaning annually (water quality dependent, many are 2x/YR) At $500.00 per visit. Lastly, the other water treatment and filtration equipment that may also be needed must be running properly. Contaminated water can and does clog up the radon system. Just as with the Airwell approach, when Iron in water is oxidized (aerated), it turns red. If water contains Iron, it will turn red. As such other filtration to remove Iron would be required. CZ does not do this work.

AirWell Method

Outside at the well-head a small low-voltage air pump is attached to the well casing. A pipe with an aeration section is inserted into the well bore, down to the bottom of the well. Pressurized air is fed into this pipe causing water that was at the bottom of the well to be air-lifted to the top of the water column. This recirculation of the water oxidizes the water contaminants in the well. Otherwise trapped gasses like Radon and Methane escape. Contaminant minerals come out of solution and drop harmlessly to the bottom of the well. If this sounds really simple, good, it is.

Pro: Simple. Less expensive than Bubble-up approach. Easy Home-Owner maintenance. Cheap to run. Quiet.
Con: If you have Radon levels over 100,000 pCi/L, Certain combinations of water chemistry (rare). Just as with the Bubble-Up approach, when Iron in water is oxidized (aerated), it turns red. If water contains Iron, it will turn red. As such other filtration to remove Iron would be required. CZ does not do this work.

For an in-depth look at the science and technology of the AirWell Click here!

Or visit the Airwell website.